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playing with boost::unique_futures
by Conoscenza Silente 11 Mar '10

11 Mar '10

Hi all I am doing my first steps in using boost::unique_future and below the example of usage that arose my question. Looking at the C++0x I can see that you can create a future using std::async. If I understood correctly the good thing of it is that, based on some policy that I imaging to be related to number of core availables+other things, std::async will choice for you whether to run your functions in a specific thread, or using a ThreadPool or other available resources. With the code I did below, once I have 2 functions I am forced to use alwyas 2 threads. Do you know what are the alternatives in Boost/ Boost Thread and if right now there is/there will be an equivalent of std::async in Boost? Thanks int firstBigOne(){ for( int i = 0; i < 3; i++ ){ std::cout << "firstBigOne" << std::endl; boost::this_thread::sleep( boost::posix_time::milliseconds(200) ); } return 10; } int secondBigOne(){ for( int i = 0; i < 4; i++ ){ std::cout << "secondBigONe" << std::endl; boost::this_thread::sleep( boost::posix_time::milliseconds(200) ); } return 20; } void TestC(){ try{ boost::packaged_task<int> pt1(firstBigOne); boost::packaged_task<int> pt2(secondBigOne); boost::unique_future<int> f1=pt1.get_future(); boost::unique_future<int> f2=pt2.get_future(); boost::thread t1( boost::move( pt1 )); boost::thread t2( boost::move( pt2 ));

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[asio] Callbacks not getting called
by Tom Kent 11 Mar '10

11 Mar '10

I posted something about this a couple days ago, but it was fairly complex, and had some typos in it. Here's another try, where I've trimmed it down even more, trying to get to the meat of the problem. I'm just using c-style functions for the callback now and its still not working. What I am doing: 1. Start a server process 2. The server process makes an empty socket and uses it to listen (with a tcp::acceptor) for TCP connections on a port (10010 for example) 3. Start a client process 4. Have the client process create a socket connect to the server's port 5. When the server sees a client is connecting, it starts listening for data(with async_read) on the socket and creates another empty socket to listen for another TCP connection on the port 6. When the client sees that the server has connected, it sends 100 bytes of data (with async_write) and waits for the socket to tell it the send is finished...when that happens it prints a message and shuts down 7. When the server gets notified that its has data that has been read, it prints a message and shuts down I'm running on windows (originally with boost_1_38_0, but today I tired with boost_1_42_0 with the same results) and have a visual studio solution file you can get (http://boost.teeks99.com/BoostConnectionTest.zip) if you're interested. BoostConnectionServer.cpp: #include <boost/asio.hpp> #include <boost/thread.hpp> #include <iostream> using namespace boost::asio::ip; boost::asio::io_service* io_service_; tcp::acceptor* acceptor_; tcp::socket* sock1_; tcp::socket* sock2_; bool conn1Done_; bool gotTransfer_; void HandleAccept(const boost::system::error_code& error) { conn1Done_ = true; sock2_ = new tcp::socket(*io_service_); acceptor_->async_accept(*sock2_, HandleAccept); } // Doesn't compile with one param like the chat example //void HandleTransfer(const boost::system::error_code& error) // Compiles with 2 params, but never gets called void HandleTransfer(const boost::system::error_code& error, size_t bytes) { if(!error) gotTransfer_; else std::cout << error << std::endl; } int main(int argc, char* argv[]) { io_service_ = new boost::asio::io_service(); conn1Done_ = false; gotTransfer_ = false; sock1_ = new tcp::socket(*io_service_); tcp::endpoint endpoint(tcp::v4(), 10011); acceptor_ = new tcp::acceptor(*io_service_, endpoint); acceptor_->async_accept(*sock1_, HandleAccept); boost::thread t(boost::bind(&boost::asio::io_service::run, io_service_)); while(!conn1Done_) { boost::this_thread::sleep(boost::posix_time::millisec(1)); } std::cout << "Accepted incoming connection\n"; char data[100]; boost::asio::async_read(*sock1_, boost::asio::buffer(data, 100), HandleTransfer); while(!gotTransfer_) { boost::this_thread::sleep(boost::posix_time::millisec(1)); } std::cout << "Success!\n"; return 0; } BoostConnectionClient.cpp: #include <boost/asio.hpp> #include <boost/thread.hpp> #include <iostream> using namespace boost::asio::ip; boost::asio::io_service* io_service_; tcp::socket* sock_; bool connected_; bool gotTransfer_; void HandleConnect(const boost::system::error_code& error) { if(!error) connected_ = true; else std::cout << error << std::endl; } // Doesn't compile with one param like the chat example //void HandleTransfer(const boost::system::error_code& error) // Compiles with 2 params, but never gets called void HandleTransfer(const boost::system::error_code& error, size_t bytes) { if(!error) gotTransfer_; else std::cout << error << std::endl; } int main(int argc, char* argv[]) { connected_ = false; gotTransfer_ = false; io_service_ = new boost::asio::io_service(); sock_ = new tcp::socket(*io_service_); tcp::endpoint ep(address::from_string("127.0.0.1"), 10011); sock_->async_connect(ep, HandleConnect); boost::thread t(boost::bind(&boost::asio::io_service::run, io_service_)); while(!connected_) { boost::this_thread::sleep(boost::posix_time::millisec(1)); } std::cout << "Connected\n"; char data[100]; data[0] = 0; data[1] = 1; data[2] = 2; data[3] = 3; data[99] = 99; boost::asio::async_write(*sock_, boost::asio::buffer(data, 100), HandleTransfer); while(!gotTransfer_) { boost::this_thread::sleep(boost::posix_time::millisec(1)); } std::cout << "Done\n"; return 0; } Any thoughts on what I'm doing incorrectly here would be much appreciated. Thanks in advance :-) Tom Kent

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State machines and undedefined symbols
by s_a_white＠email.com 11 Mar '10

11 Mar '10

Hi, I've inherited some code that currently compiles and runs under Linux (gcc 4.2.1) and am looking to switch to Windows using the vs 2003. Unfortunately the code fails to compile with undefined symbols. An example of the code is as follows: #include <boost/statechart/event.hpp> #include <boost/statechart/state_machine.hpp> #include <boost/statechart/simple_state.hpp> #include <boost/statechart/transition.hpp> #include <iostream> namespace sc = boost::statechart; struct EvStartStop : sc::event< EvStartStop > {}; struct EvReset : sc::event< EvReset > {}; struct Active; struct Stopped; struct Running; struct StopWatch : sc::state_machine< StopWatch, Active > {}; struct Active : sc::simple_state< Active, StopWatch, Stopped > { typedef sc::transition< EvReset, Active > reactions; }; struct Stopped : sc::simple_state< Stopped, Active > { typedef sc::transition< EvStartStop, Running > reactions; }; int main() { return 0; } I'm aware that the code is incomplete as Running is only forward declared. It is provided this way since the real model under Linux is broken up across multiple headers rather than all being in one header. Under Linux the above code compiles without an issue but vs 2003 complains about Running being undefined. Removing sc::transition< EvStartStop, Running > makes the compilation problem disappear. A similiar issue exists for Windows if Running was defined but uses an inner state that was only foward declared. Again Linux seems to have no problems. Can anyone suggest if what is being done here is broken under vs 2003, or should not be allowed under gcc? Are there workarounds for the boost headers for vs 2003 or recommendations to allow splitting the state machine across multiple headers? Best Regards, Simon

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Re: [Boost-users] [Boost-uses] [asio] Callbacks not getting called
by Tom Kent 11 Mar '10

11 Mar '10

One important detail I forgot in my last post. When I run in the server and the client has already sent its payload (several seconds ago) and the server is just waiting in the loop for its callback. At this point, if I break in the debugger, I can see that indeed the data has been received and put into the buffer that was setup to receive it!!! So the transfer is going well, it is just that the callback isn't getting called. Tom -------- Original Message -------- Subject: [asio] Callbacks not getting called Date: Thu, 11 Mar 2010 14:08:46 -0600 From: Tom Kent <lists(a)teeks99.com> To: boost-users(a)lists.boost.org I posted something about this a couple days ago, but it was fairly complex, and had some typos in it. Here's another try, where I've trimmed it down even more, trying to get to the meat of the problem. I'm just using c-style functions for the callback now and its still not working. What I am doing: 1. Start a server process 2. The server process makes an empty socket and uses it to listen (with a tcp::acceptor) for TCP connections on a port (10010 for example) 3. Start a client process 4. Have the client process create a socket connect to the server's port 5. When the server sees a client is connecting, it starts listening for data(with async_read) on the socket and creates another empty socket to listen for another TCP connection on the port 6. When the client sees that the server has connected, it sends 100 bytes of data (with async_write) and waits for the socket to tell it the send is finished...when that happens it prints a message and shuts down 7. When the server gets notified that its has data that has been read, it prints a message and shuts down I'm running on windows (originally with boost_1_38_0, but today I tired with boost_1_42_0 with the same results) and have a visual studio solution file you can get (http://boost.teeks99.com/BoostConnectionTest.zip) if you're interested. BoostConnectionServer.cpp: #include <boost/asio.hpp> #include <boost/thread.hpp> #include <iostream> using namespace boost::asio::ip; boost::asio::io_service* io_service_; tcp::acceptor* acceptor_; tcp::socket* sock1_; tcp::socket* sock2_; bool conn1Done_; bool gotTransfer_; void HandleAccept(const boost::system::error_code& error) { conn1Done_ = true; sock2_ = new tcp::socket(*io_service_); acceptor_->async_accept(*sock2_, HandleAccept); } // Doesn't compile with one param like the chat example //void HandleTransfer(const boost::system::error_code& error) // Compiles with 2 params, but never gets called void HandleTransfer(const boost::system::error_code& error, size_t bytes) { if(!error) gotTransfer_; else std::cout << error << std::endl; } int main(int argc, char* argv[]) { io_service_ = new boost::asio::io_service(); conn1Done_ = false; gotTransfer_ = false; sock1_ = new tcp::socket(*io_service_); tcp::endpoint endpoint(tcp::v4(), 10011); acceptor_ = new tcp::acceptor(*io_service_, endpoint); acceptor_->async_accept(*sock1_, HandleAccept); boost::thread t(boost::bind(&boost::asio::io_service::run, io_service_)); while(!conn1Done_) { boost::this_thread::sleep(boost::posix_time::millisec(1)); } std::cout << "Accepted incoming connection\n"; char data[100]; boost::asio::async_read(*sock1_, boost::asio::buffer(data, 100), HandleTransfer); while(!gotTransfer_) { boost::this_thread::sleep(boost::posix_time::millisec(1)); } std::cout << "Success!\n"; return 0; } BoostConnectionClient.cpp: #include <boost/asio.hpp> #include <boost/thread.hpp> #include <iostream> using namespace boost::asio::ip; boost::asio::io_service* io_service_; tcp::socket* sock_; bool connected_; bool gotTransfer_; void HandleConnect(const boost::system::error_code& error) { if(!error) connected_ = true; else std::cout << error << std::endl; } // Doesn't compile with one param like the chat example //void HandleTransfer(const boost::system::error_code& error) // Compiles with 2 params, but never gets called void HandleTransfer(const boost::system::error_code& error, size_t bytes) { if(!error) gotTransfer_; else std::cout << error << std::endl; } int main(int argc, char* argv[]) { connected_ = false; gotTransfer_ = false; io_service_ = new boost::asio::io_service(); sock_ = new tcp::socket(*io_service_); tcp::endpoint ep(address::from_string("127.0.0.1"), 10011); sock_->async_connect(ep, HandleConnect); boost::thread t(boost::bind(&boost::asio::io_service::run, io_service_)); while(!connected_) { boost::this_thread::sleep(boost::posix_time::millisec(1)); } std::cout << "Connected\n"; char data[100]; data[0] = 0; data[1] = 1; data[2] = 2; data[3] = 3; data[99] = 99; boost::asio::async_write(*sock_, boost::asio::buffer(data, 100), HandleTransfer); while(!gotTransfer_) { boost::this_thread::sleep(boost::posix_time::millisec(1)); } std::cout << "Done\n"; return 0; } Any thoughts on what I'm doing incorrectly here would be much appreciated. Thanks in advance :-) Tom Kent

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Boost.Array intialisation
by gast128 11 Mar '10

11 Mar '10

Hello all, the documentation describes that Boost.Array deliberately omits constructors to allow intialisation in functions: void F() { boost::array<int, 4> a2 = { 1, 2, 3 }; } That's fine, but how does one intialise a Boost.Array in member intialiser list, e.g.: struct Foo { Foo() : m_a(???) { } boost::array<int, 4> m_a; }; Ofc initialisation can be done in the body of the constructor, but this does not work for const member variables. Also above design choice is contradictionary with STL containers, which gets default initialised. (e.g. m_v (3); ofc there is a difference, since vectors have a dynamic size). thx in advance

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Boost python library build error
by Yogesh Arora 11 Mar '10

11 Mar '10

Hi I am using Boost 1.39.0 on Sun os. I have compiled boost libraries myself with sun toolset using these options ./bootstrap.sh --with-toolset=sun While building i get this error ./boost/python/detail/wrap_python.hpp", line 78: Error, usererror: #error Python 2.2 or higher is required for this version of Boost.Python i have python 2.4 installed on my machine, and it is in my PATH variable, however boost build is not picking it up. Is there somehow i can explicitly specify in the jam command line. ---- Yogesh

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Boost.regex expression construction
by Shaolin 11 Mar '10

11 Mar '10

Hi Guys I am using boost.regex to check whether a string has opening and closing brackets. The problem is the expression doesnt work. I have tried all sorts of combos and read up the doc too to no avail. Can someone tell me whether the following does what its supposed to (i.e. look for opening/closing brackets in a string): boost::regex e("[\$\$]"); /*check for opening/closing brackets*/ Regards

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[multiarray] Regression with MSVC10 assigning sub-array to array?
by Jesse Perla 11 Mar '10

11 Mar '10

It looks to me like there is a regression with multi_array in boost 1.42 using the MSVC10 RC. The problem is when you assign a sub_array to an array. This code works fine on MSVC9 and Intel 11.1 on windows. Any easy patches that could fix this, or am I missing something? #include <boost/multi_array.hpp> int main(int argc, char* argv[]) { boost::multi_array<double, 3> f_values(boost::extents[5][6][7]); //A boost::multidimensional object boost::detail::multi_array::sub_array<double, 2> sub_f = f_values[2]; //Works boost::multi_array<double, 2> sub_f2 = f_values[2]; //Fails, used to work } =============================== The error novel (ignoring the warning about unsafe iterators) is: 1>C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\include\xutility(2216): error C2665: 'std::_Copy_impl' : none of the 2 overloads could convert all the argument types 1> C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\include\xutility(2182): could be '_OutIt std::_Copy_impl<_InIt,_OutIt>(_InIt,_InIt,_OutIt,std::input_iterator_tag,std::output_iterator_tag)' 1> with 1> [ 1> _OutIt=boost::detail::multi_array::array_iterator<double,double *,boost::mpl::size_t<2>,boost::detail::multi_array::sub_array<double,1>>, 1> _InIt=boost::detail::multi_array::array_iterator<double,const double *,boost::mpl::size_t<2>,boost::detail::multi_array::const_sub_array<double,1>> 1> ] 1> C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\include\xutility(2191): or '_OutIt std::_Copy_impl<_InIt,_OutIt>(_InIt,_InIt,_OutIt,std::random_access_iterator_tag,std::random_access_iterator_tag)' 1> with 1> [ 1> _OutIt=boost::detail::multi_array::array_iterator<double,double *,boost::mpl::size_t<2>,boost::detail::multi_array::sub_array<double,1>>, 1> _InIt=boost::detail::multi_array::array_iterator<double,const double *,boost::mpl::size_t<2>,boost::detail::multi_array::const_sub_array<double,1>> 1> ] 1> while trying to match the argument list '(boost::detail::multi_array::array_iterator<T,TPtr,NumDims,Reference>, boost::detail::multi_array::array_iterator<T,TPtr,NumDims,Reference>, boost::detail::multi_array::array_iterator<T,TPtr,NumDims,Reference>, boost::detail::iterator_category_with_traversal<Category,Traversal>, boost::detail::iterator_category_with_traversal<Category,Traversal>)' 1> with 1> [ 1> T=double, 1> TPtr=const double *, 1> NumDims=boost::mpl::size_t<2>, 1> Reference=boost::detail::multi_array::const_sub_array<double,1> 1> ] 1> and 1> [ 1> T=double, 1> TPtr=const double *, 1> NumDims=boost::mpl::size_t<2>, 1> Reference=boost::detail::multi_array::const_sub_array<double,1> 1> ] 1> and 1> [ 1> T=double, 1> TPtr=double *, 1> NumDims=boost::mpl::size_t<2>, 1> Reference=boost::detail::multi_array::sub_array<double,1> 1> ] 1> and 1> [ 1> Category=std::input_iterator_tag, 1> Traversal=boost::random_access_traversal_tag 1> ] 1> and 1> [ 1> Category=std::input_iterator_tag, 1> Traversal=boost::random_access_traversal_tag 1> ] 1> C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\include\xutility(2227) : see reference to function template instantiation '_OutIt std::_Copy_impl<_Iter,_OutIt>(_InIt,_InIt,_OutIt,std::tr1::false_type)' being compiled 1> with 1> [ 1> _OutIt=boost::detail::multi_array::array_iterator<double,double *,boost::mpl::size_t<2>,boost::detail::multi_array::sub_array<double,1>>, 1> _Iter=boost::detail::multi_array::array_iterator<double,const double *,boost::mpl::size_t<2>,boost::detail::multi_array::const_sub_array<double,1>>, 1> _InIt=boost::detail::multi_array::array_iterator<double,const double *,boost::mpl::size_t<2>,boost::detail::multi_array::const_sub_array<double,1>> 1> ] 1> C:\working\libraries\boost\boost/multi_array.hpp(337) : see reference to function template instantiation '_OutIt std::copy<boost::detail::multi_array::array_iterator<T,TPtr,NumDims,Reference>,boost::detail::multi_array::array_iterator<T,T *,NumDims,boost::detail::multi_array::sub_array<T,1>>>(_InIt,_InIt,_OutIt)' being compiled 1> with 1> [ 1> _OutIt=boost::detail::multi_array::array_iterator<double,double *,boost::mpl::size_t<2>,boost::detail::multi_array::sub_array<double,1>>, 1> T=double, 1> TPtr=const double *, 1> NumDims=boost::mpl::size_t<2>, 1> Reference=boost::detail::multi_array::const_sub_array<double,1>, 1> _InIt=boost::detail::multi_array::array_iterator<double,const double *,boost::mpl::size_t<2>,boost::detail::multi_array::const_sub_array<double,1>> 1> ] 1> C:\working\libraries\boost\boost/multi_array.hpp(332) : while compiling class template member function 'boost::multi_array<T,NumDims>::multi_array(const boost::detail::multi_array::sub_array<T,2> &)' 1> with 1> [ 1> T=double, 1> NumDims=2 1> ] 1> ..\test.cpp(14) : see reference to class template instantiation 'boost::multi_array<T,NumDims>' being compiled 1> with 1> [ 1> T=double, 1> NumDims=2 1> ]

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Re: [Boost-users] [Serialization] Strange giant warning
by Avi Bahra 11 Mar '10

11 Mar '10

>I'm speaking from memory and it's possible that the situation >has changed since 1.39 and the message is now spurious. If so >send a small test case which shows that the library has a bug. > >Robert Ramey The case you highlight is correct, and should produce a warning message. However a small variation shown below produces the same message, which I believe is wrong . This warning message is present in1.39, 1.40 on HPUX and AIX , on Linux/gcc there is _no_ such warning. class concrete { ... }; class base { ~virtual base(); ... vector<boost::shared_ptr<concrete> > vec_; }; class derived : public base { .... }; BOOST_CLASS_EXPORT(Derived); Here you will see the same warning message, saying that class 'concrete' should be polymorphic. Best regards. Ta, Avi

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Re: [Boost-users] [Serialization] Strange giant warning
by Avi Bahra 11 Mar '10

11 Mar '10

This is caused by a bug in the boost serialisation, well at least in 1.39 Where is assumes that shared ptr must be polymorphic I have already reported a similar problem. i.e >>... boost_1_39_0/boost/ >>serialization/extended_type_info_typeid.hpp", line >> 88: >> warning #2414-D: delete of pointer to incomplete class >> BOOST_STATIC_WARNING(boost::is_polymorphic<T>::value); >> ^detected during: >> instantiation of "const boost::serialization::extended_type_info >> *boost::serialization::extended_type_info_typeid<T>::get_derived_extended_type_info(const >> T &) const [with T=Concrete]" at line 92 of >> "/scratch/ma/emos/ma0/hpia64/boost/boost_1_39_0/boost/archive/shared_ptr_helper.hpp" >> >> >> It looks like if we are serialising via a base ptr, and the >> base class is serialising concrete data member via a shared ptr, >> it has assumed that the type must be polymorphic. This does >> not seem right to me ? The hacky way to stop your warning message would be add a dummy virtual function. Best regards, Ta, Avi

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Regex alternation in xpressive
by Surya Kiran Gullapalli 11 Mar '10

11 Mar '10

Hello all, I'm trying to match ordinal numbers (1st, 2nd, 3rd, 4th etc) like this. *xpr::as_xpr ("Some Text") * * >> xpr::repeat<1, 2>(_d) * * >> ("st"|"nd"|"rd"|"th") ;* Compilation fails at 3rd line with the following error error C2296: '|' : illegal, left operand has type 'const char [3]' ; what am i missing ? did I give the construct correctly ? Thanks in advance, Surya

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BOOST_SERIALIZATION_BASE_OBJECT_NVP not convenient for template base class and XML archive
by Alain KOCELNIAK 11 Mar '10

11 Mar '10

template < class eArchive > void MtxAnsFunctionIntegerPipe::serialize( eArchive& aArchive, const unsigned int aVersion ) { aArchive & BOOST_SERIALIZATION_BASE_OBJECT_NVP( MtxAnmFunctionTpl<int> ) ; aArchive & BOOST_SERIALIZATION_NVP( mVariable ) ; } #define BOOST_SERIALIZATION_BASE_OBJECT_NVP(name) \ boost::serialization::make_nvp( \ BOOST_PP_STRINGIZE(name), \ boost::serialization::base_object<name >(*this) \ The stringized class name ("MtxAnmFunctionTpl<int>") generate a non valid XML tag name (due to < > ) There is no BOOST_SERIALIZATION_BASE_OBJECT_NVP2( type, tag) macro (as BOOST_CLASS_EXPORT_KEY2(class, key) for BOOST_EXPORT_CLASS_KEY(class) ). Such a macro is necessary to write things like : aArchive & BOOST_SERIALIZATION_BASE_OBJECT_NVP2( MtxAnmFunctionTpl<int>, "MtxAnmFunctionTplInt" ) ; In the next release ? Alain K.

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[function] dynamic function factory
by Alexander Lamaison 11 Mar '10

11 Mar '10

I'm trying to write a little wrapper round Windows GetProcAddress (dlsym equivalent?) that takes a function name by string, loads it dynamically and returns it as a boost::function. I'm having trouble getting my code to accept the same type of signatures as boost::function. E.g.: template<typename Signature> boost::function<Signature> proc_address( hmodule hmod, const std::string& name) { return boost::function<Signature>(GetProcAddress(hmod, name.c_str()); } Where GetProcAddress returns a int (*)() which you cast to the function signature you're expecting. The problem is that when I call: boost::function<int (int)> func; func = proc_address<int (int)>(hmod, "GetKeyboardInfo"); The compiler (MSVC 2005) complains about a ) after the int: error C2144: syntax error : 'int' should be preceded by ')' error C2563: mismatch in formal parameter list Am I trying to reuse boost::function the wrong way? I also tried making a functor instead but I have no idea what to put as the parameter list for operator(): template<typename Signature> class dynamic_function { public: dynamic_function(hmodule hmod, const std::string& name) : m_func(GetProcAddress(hmod, name.c_str())) {} operator()(...what goes here?...) { return m_func( ... what ... ); } private: boost::function<Signature> m_func; }; Any help is greatly appreciated. Alex

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integer constant too large for 'long' type
by David Kaplan 11 Mar '10

11 Mar '10

I'm having problems compiling this line of code on a 32bit system: boost::uniform_int<uint64_t> r(0,0xffffffffffffffff); compile-time error: "integer constant too large for 'long' type" compiled fine on my 64 bit machine. Also sizeof(uint64_t) on both machines is correct at 8 bytes (typedef'd as long long int on the 32bit machine). Any ideas?

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Boost.Asio chat example chat_client have 3 connections, what other 2 connections doing?
by l.jay Yuan 11 Mar '10

11 Mar '10

Boost.Asio chat example chat_client have 3 connections, what other 2 connections doing? Builded on WinXP. The implementation is strange.

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I'm creating an abstraction layer to work with C++, thought you might be interested
by Alan Tennant 10 Mar '10

10 Mar '10

I'm creating an abstraction layer to work with C++, thought you might be interested. Attached are the files required to use it. What it does should be apparent by reading from the top of main () and running the code, you might have to redirect the 4 #includes if you set up your directory structure differently from me. Note stuff.h only contains one function that is required. The program uses an object called obj to achieve the things it does, it does not add this functionality into the bottom level of C++. The key concepts of an obj include: Access members of objects using std::string's Strings can be transferred and stored a lot more easily than types. They can also be combined more easily, a trivial example is ".toString" being made of two parts. Finally they can easily be used as parameters so a function could take some data and member names as parameters. Individual obj members can be added and removed one at a time. One member function can easily be used by several different types. A function can look at aspects of the object it belongs to in order to work out how to behave without any problems or inconsistencies created by the underlying workings of C++. There is no need for all the empty (or otherwise meaningless) member functions that occur near the top of the tree in programs with lots of inheritance, although inheritance possibilities work differently the same sorts of results can be achieved just as easily with less code. CSS like parameters with names and values where any number of them can be used without having to specify the information in advance. Uses boost::any's extensively but you don't have to wrap and unwrap them yourself, less needing to repeat and know definite information about types all the time. Little difference between accessing different types of members such as objects or functions. Want obj's to behave in a fundamentally different way, write members yourself for object without having to edit my files and add them to obj's you create. I'm sure some of this is possible in other ways and put into code as you need it instead of being one big chunk but I think this abstraction layer is useful. I could also use #defines to simplify and enhance the feel of writing code for the user, for example adding some symbols to represent key features instead of having to write a whole word between .'s. It's not as great as it could be at the moment. I think it does everything by copy making it slow and making it so you can't change members when you access them, I wish for it to do everything by pointer to new memory is such a way as it has the Java feal of doing everything the fast way without having to think about it, it could even be smart enough to notice that bools are not efficient this way. I'm not sure how I will fix these things regarding things like how "template <typename T*>" works. Also when you do have to use normal types it might be hard to implement template functions on the obj functions you write. later I will implement removing a member, setting up a type containing various members, more easily creating objects with lots of miscellaneous members (using only one line of code) etc... p.s. I don't have lots of time at the moment to implement due to other commitments, if you like this consider helping with some of it.

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[proto] const-ness of references
by Manjunath Kudlur 10 Mar '10

10 Mar '10

>From reading the documentation, I understand that expressions and objects that are wrapped in proto::terminal<> are held by reference. In the following code, in the "assign" grammar, I match proto::terminal<Var<proto::_> > and call _assign on proto::_value. As expected, a reference to the object held in the terminal gets passed to the callable transform, and I can assign some value to it. template<typename VT> struct Var { VT value; void assign(const VT v) { value = v; } }; struct _assign : proto::callable { typedef void result_type; template<typename VT> result_type operator()(Var<VT> &var) const { var.assign(20); } }; struct assign : proto::or_< proto::when<proto::terminal<Var<proto::_> >, _assign(proto::_value)> > {}; typedef proto::terminal<Var<int> >::type int32_; int main() { int32_ a,b,c; assign()(a); std::cout << proto::value(a).value << std::endl; } Now, I add the following rules to assign grammar : struct assign : proto::or_< proto::when<proto::terminal<Var<proto::_> >, _assign(proto::_value)>, proto::when<proto::assign<proto::terminal<Var<proto::_> >, proto::literal<proto::_> >, _assign(proto::_value(proto::_left), proto::_value(proto::_right))>, proto::when<proto::function<proto::terminal<Var<proto::_> >, proto::literal<proto::_> >, _assign(proto::_value(proto::_left), proto::_value(proto::_right))> > {}; and the following operator() overload to _assign : template<typename VT> result_type operator()(Var<VT> &var, const VT val) const { var.assign(val); } I can merrily call assign()(a=10) and I get the expected behaviour. But when I call assign()(a(20)), I get a compilation error saying that there is no match for operator()(const Var<int> &, const int &). Why is that when I call proto::_value(proto::_left) on a proto::function expression, a *const* reference gets passed to the transform? Did I miss some part of the documentation where this is explained? Manjunath

2 9

template concept question
by Alan Tennant 10 Mar '10

10 Mar '10

I was reading about boosts concepts and I thought. Can I ask inside a template function if a member exists on a parameter of the function. For example. template <typename T> void func(T in) { exists(in, foo); } Where the "exists" line would return true if "in" had a member "foo" otherwise false.

4 9

[Gil new_io] Some questions and remarks
by Olivier Tournaire 10 Mar '10

10 Mar '10

Hi all, I have just checkout gil-contributions svn repo ( http://code.google.com/p/gil-contributions/) in order to test new_io in which I am really interested. Thank you for this very usefull job! I have however some remarks and questions about some compilation issues. 0) The code seems to have been written and tested on Windows. Am I right (see my remarks thereafter)? For ex., why do you use "\\" in paths (paths.hpp) and not "/"? 1) Which Boost version is required? I first tried with 1.40, but it did not work because of missing accessors in boost::gil::variant (index() and bits()). Did they appear in 1.41 or 1.42? With 1.42, this issue is solved. 2) While compiling tests, I ran into some issues. I am running the code on an Ubuntu 9.10, with g++-4.3.4. I was able to fix some of them, but others are still problematic: 2.1) For each test, I have to add at the beginning the 2 following lines: #define BOOST_TEST_DYN_LINK #define BOOST_TEST_MODULE my application tests It probably comes from my little knowledge of boost unit_test_framework. Could you explain? 2.2) For each test, the compiler gave the following error: /usr/local/include/boost/gil/extension/io_new/detail/dynamic_io_new.hpp:75: error: there are no arguments to ‘io_error’ that depend on a template parameter, so a declaration of ‘io_error’ must be available I simply add in *[...]/detail/dynamic_io_new.hpp* an unclude directive at the beginning of the file : #include <boost/gil/extension/io/io_error.hpp>. Still do not understand how it can work wihtout this ... 2.3) I had a similar error with *[...]/formats/bmp/read.hpp*: /usr/local/include/boost/gil/extension/io_new/formats/bmp/read.hpp:833: error: there are no arguments to ‘get_info’ that depend on a template parameter, so a declaration of ‘get_info’ must be available I simply changed line 833 from get_info() to parent_t::get_info(). Now works. 2.4) Some typename are missing (still do not know how visual can infer types ...): - [...]/formats/jpeg/read.hpp, line 336: *typename*Image::view_t - [...]/formats/bmp/is_allowed.hpp, line 73: *typename*View::value_type - [...]/formats/pnm/read.hpp, line 419: *typename* Image::view_t Everything works with these changes. 2.5) png_read_test failed. Obviously, this is a portability issue. PNG filenames for testing are uppercase, while they are lowercase in the test code. I think that is also missing in the code the path to png files. For example, in basic_format_test, instead of test_file< gray1_image_t >( "basn0g01.png" ); it soulhd be: test_file< gray1_image_t >(* png_in + "BASN0G01.PNG"* ); I did not rename all files, so I am unable to try the test. 2.6) Some tests fail to compile or link. Here are the errors: - *all_formats_test.cpp*: In file included from /usr/include/png.h:481, from /usr/local/include/boost/gil/extension/io_new/png_tags.hpp:23, from /usr/local/include/boost/gil/extension/io_new/png_read.hpp:22, from /usr/local/include/boost/gil/extension/io_new/png_all.hpp:22, from /home/olivier/work/dev/lib/gil-contributions-read-only/gil_2/libs/gil/io_new/test/all_formats_test.cpp:7: /usr/include/pngconf.h:335: error: expected constructor, destructor, or type conversion before ‘.’ token /usr/include/pngconf.h:336: error: ‘__dont__’ does not name a type - *pnm_reads_test.cpp*: pnm_read_test.cpp.o: In function `pnm_test::read_header_test::test_method()': pnm_read_test.cpp:(.text+0x24c0): undefined reference to `boost::gil::pnm_image_type::_color_asc' collect2: ld returned 1 exit status Do not really understand since _color_asc is a typedef defined in pnm_tags.hpp ... - *jpeg_old_test.cpp* (sorry for the message ...): /usr/local/include/boost/gil/extension/io_new/formats/jpeg/write.hpp: In function ‘typename BinaryOp::result_type boost::gil::detail::apply_operation(const boost::gil::variant<Types>&, const Info&, BinaryOp) [with Types1 = boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgba8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray16_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray8_pixel_t*> > >, boost::mpl::vector0<mpl_::na>, 0>, 0>, 0>, 0>, Info = boost::gil::image_write_info<boost::gil::jpeg_tag, boost::gil::detail::no_log>, BinaryOp = boost::gil::detail::dynamic_io_fnobj<boost::gil::detail::jpeg_write_is_supported, boost::gil::detail::writer<boost::gil::detail::file_stream_device<boost::gil::jpeg_tag>, boost::gil::jpeg_tag, boost::gil::detail::no_log> >]’: /usr/local/include/boost/gil/extension/io_new/formats/jpeg/write.hpp:283: instantiated from ‘void boost::gil::detail::dynamic_image_writer<Device, boost::gil::jpeg_tag, boost::gil::detail::no_log>::apply(const boost::gil::any_image_view<Views>&, const boost::gil::image_write_info<boost::gil::jpeg_tag, boost::gil::detail::no_log>&) [with Views = boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgba8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray16_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray8_pixel_t*> > >, boost::mpl::vector0<mpl_::na>, 0>, 0>, 0>, 0>, Device = boost::gil::detail::file_stream_device<boost::gil::jpeg_tag>]’ /usr/local/include/boost/gil/extension/io_new/detail/write_view.hpp:302: instantiated from ‘void boost::gil::write_view(Device&, const boost::gil::any_image_view<Types2>&, const boost::gil::image_write_info<FormatTag, Log>&, typename boost::enable_if<typename boost::mpl::and_<typename boost::gil::detail::is_output_device<IODevice>::type, typename boost::gil::is_format_tag<FormatTag>::type, mpl_::bool_<true>, mpl_::bool_<true>, mpl_::bool_<true> >::type, void>::type*) [with Device = boost::gil::detail::file_stream_device<boost::gil::jpeg_tag>, Views = boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgba8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray16_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray8_pixel_t*> > >, boost::mpl::vector0<mpl_::na>, 0>, 0>, 0>, 0>, FormatTag = boost::gil::jpeg_tag, Log = boost::gil::detail::no_log]’ /usr/local/include/boost/gil/extension/io_new/detail/write_view.hpp:357: instantiated from ‘void boost::gil::write_view(const String&, const boost::gil::any_image_view<Types2>&, const boost::gil::image_write_info<FormatTag, Log>&, typename boost::enable_if<typename boost::mpl::and_<typename boost::gil::detail::is_supported_path_spec::type, typename boost::gil::is_format_tag<FormatTag>::type, mpl_::bool_<true>, mpl_::bool_<true>, mpl_::bool_<true> >::type, void>::type*) [with String = std::basic_string<char, std::char_traits<char>, std::allocator<char> >, Views = boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgba8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray16_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray8_pixel_t*> > >, boost::mpl::vector0<mpl_::na>, 0>, 0>, 0>, 0>, FormatTag = boost::gil::jpeg_tag, Log = boost::gil::detail::no_log]’ /usr/local/include/boost/gil/extension/io_new/jpeg_io_old.hpp:169: instantiated from ‘void boost::gil::jpeg_write_view(const String&, const View&, int) [with String = std::basic_string<char, std::char_traits<char>, std::allocator<char> >, View = boost::gil::any_image_view<boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgba8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray16_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray8_pixel_t*> > >, boost::mpl::vector0<mpl_::na>, 0>, 0>, 0>, 0> >]’ /home/olivier/work/dev/lib/gil-contributions-read-only/gil_2/libs/gil/io_new/test/jpeg_old_test.cpp:98: instantiated from here /usr/local/include/boost/gil/extension/io_new/formats/jpeg/write.hpp:243: error: invalid initialization of non-const reference of type ‘boost::gil::variant<boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgba8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray16_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray8_pixel_t*> > >, boost::mpl::vector0<mpl_::na>, 0>, 0>, 0>, 0> >::base_t&’ from a temporary of type ‘boost::gil::variant<boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgba8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray16_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray8_pixel_t*> > >, boost::mpl::vector0<mpl_::na>, 0>, 0>, 0>, 0> >::base_t’ /usr/local/include/boost/gil/extension/io_new/formats/jpeg/write.hpp:213: error: in passing argument 1 of ‘typename Op::result_type boost::gil::detail::apply_operation_base(Bits&, size_t, const Info&, Op) [with Types = boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgba8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray16_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray8_pixel_t*> > >, boost::mpl::vector0<mpl_::na>, 0>, 0>, 0>, 0>, Info = boost::gil::image_write_info<boost::gil::jpeg_tag, boost::gil::detail::no_log>, Bits = boost::gil::variant<boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgba8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::rgb8_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray16_pixel_t*> > >, boost::mpl::v_item<boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::gray8_pixel_t*> > >, boost::mpl::vector0<mpl_::na>, 0>, 0>, 0>, 0> >::base_t, Op = boost::gil::detail::dynamic_io_fnobj<boost::gil::detail::jpeg_write_is_supported, boost::gil::detail::writer<boost::gil::detail::file_stream_device<boost::gil::jpeg_tag>, boost::gil::jpeg_tag, boost::gil::detail::no_log> >]’ /usr/local/include/boost/gil/extension/io_new/formats/jpeg/write.hpp:243: error: return-statement with a value, in function returning 'void' Apart png_read_test and its case sensitive problem, all compiled and linked tests run successfully. This is a really good new! However, could you please help regarding the issues above? Please note that if you are intersted in a Linux developper/tester for gil, I am wiling to do some jobs ... Best regards, Olivier

3 8

Re: [Boost-users] [Regex] Accessing match count
by ninti＠internode.on.net 10 Mar '10

10 Mar '10

The regexes in my previous post may be borked due to email client stripping stuff out. Let's just assume that regex_consonant and regex_vowel are well formed patterns. The code below seems to be getting closer. It returns a plausible count for number of matches of regex 'expression' in string 'word': string get_m(string word) { regex c("^" + regex_consonant); regex v(regex_vowel + "$"); string re = "(" + regex_vowel + "+" + regex_consonant + "+)"; regex expression(re); string replacement = ""; word = regex_replace(word, c, replacement); word = regex_replace(word, v, replacement); boost::sregex_token_iterator itr(word.begin(), word.end(), expression); boost::sregex_token_iterator end; int size = 0; for(; itr != end; ++itr) { size++; } string s; stringstream out; out << size; s = out.str(); return s; } Is boost::sregex_token_iterator the appropriate function for subsequently counting the number of matches found in a given string? Also, don't hold back on how bad this code is, I'm here to learn! Mick

2 1

boost::timer elapsed time
by zbierak 10 Mar '10

10 Mar '10

Hi, I've been having a problem recently with boost::timer. I have the following code: #include <iostream> #include <boost/timer.hpp> int main() { boost::timer t; // (here: some initialization stuff) t.restart(); // (here: a job that takes several seconts) std::cout << "Total time: " << t.elapsed() << "s." << std::endl; } While on my windows machine it displays the correct time, when I compile it on Ubuntu, it constantly displays zero seconds, regardless how long the job really takes. Do you have any ideas why that might be happening? I'm using boost 1.40 and Ubuntu 9.04. Thanx in advance! -- View this message in context: http://old.nabble.com/boost%3A%3Atimer-elapsed-time-tp27846807p27846807.html Sent from the Boost - Users mailing list archive at Nabble.com.

2 1

[Fusion] The very basics!
by Robert Jones 10 Mar '10

10 Mar '10

I don't mind admitting that I'm finding Fusion a struggle to get my head round; there's something about the compile time/run time duality that makes my brain hurt! So, a really basic question... When I write this, pretty much verbatim from the examples, despite there being the appearance of a loop, this is in fact a linear invocation of three calls to print::operator(), and since the fusion vector is entirely known at compile time, as all fusion types must be, regardless of how constructed, this "loop" is completely "unrolled" at compile time. Is this correct? Thanks, - Rob. #include <typeinfo> #include <iostream> #include <boost/fusion/include/sequence.hpp> #include <boost/fusion/include/algorithm.hpp> struct print { template <typename T> void operator()(T const& x) const { std::cout << x << " "; } }; int main( ) { using namespace boost::fusion; vector<int, char, std::string> stuff(1, 'x', "howdy"); for_each(stuff, print()); std::cout << std::endl; }

2 1

Can't compile boost::asio
by Daniel V 10 Mar '10

10 Mar '10

Hi, I'm trying to compile the client example found in http://www.boost.org/doc/libs/1_42_0/doc/html/boost_asio/tutorial/tutdaytim… tutorials), but I get the following errors: g++ -o dist/Debug/GNU-MacOSX/socketclient build/Debug/GNU-MacOSX/main.o Undefined symbols: "boost::system::get_system_category()", referenced from: boost::asio::error::get_system_category() in main.o boost::system::error_code::error_code()in main.o __static_initialization_and_destruction_0(int, int)in main.o __static_initialization_and_destruction_0(int, int)in main.o "boost::system::get_generic_category()", referenced from: __static_initialization_and_destruction_0(int, int)in main.o __static_initialization_and_destruction_0(int, int)in main.o __static_initialization_and_destruction_0(int, int)in main.o ld: symbol(s) not found collect2: ld returned 1 exit status make[2]: *** [dist/Debug/GNU-MacOSX/socketclient] Error 1 make[1]: *** [.build-conf] Error 2 make: *** [.build-impl] Error 2 BUILD FAILED (exit value 2, total time: 2s) Any idea why this is failing? Thanks Dann

7 7

[Regex] Accessing match count
by ninti＠internode.on.net 10 Mar '10

10 Mar '10

Newbie here trying to reimplement PHP's preg_match_all() function in C++. I'm rewriting a PHP class which functions as a Porter Stemmer. I seem to have the regex_replace code working nicely but am now stuck on regex_match/regex_search. I want to count the number of times a regex matches within a string. The regex attempts to match all occurrences of one+ vowels followed by one+ consonants (known as 'm' or measure, roughly equivalent to a syllable). The original PHP function is as follows: private static function m($str) { $c = '(?:[bcdfghjklmnpqrstvwxz]|(?<=[aeiou])y|^y)'; $v = '(?:[aeiou]|(?<![aeiou])y)'; $str = preg_replace("#^$c+#", '', $str); $str = preg_replace("#$v+$#", '', $str); preg_match_all("#($v+$c+)#", $str, $matches); return count($matches[1]); } So all I'm interested in here is the number of matches. I'm afraid I'm not even really sure which boost regex function I should be using, it seems like regex_search may be the correct choice as I'm not matching a whole string. This is what I've got so far: using namespace std; using namespace boost; string regex_vowel = "(?:[aeiou]|(?<![aeiou])y)"; string regex_consonant = "(?:[bcdfghjklmnpqrstvwxz]|(?<=[aeiou])y|^y)"; string get_m(string word) { regex c("^" + regex_consonant); regex v(regex_vowel + "$"); string replacement = ""; word = regex_replace(word, c, replacement); word = regex_replace(word, v, replacement); [ ... so far so good, this does the same as the first four lines of the PHP code above ... ] string re = "(" + regex_vowel + "+" + regex_consonant + "+)"; regex expression(re); string::const_iterator start, end; start = word.begin(); end = word.end(); match_results<string::const_iterator> what; match_flag_type flags = match_default | match_partial; regex_search(start, end, what, expression, flags); string thing = what[1]; int size = thing.size(); cout << what[1] << endl; string s; stringstream out; out << size; s = out.str(); return s; } This does not replicate the last two lines of PHP code above, instead returning the number of characters in a substring of sorts. So yes, I'm lost! Have tried several variations/possibilities but can't find a good example to work with. Have tried some much simpler variations they're not working either. TIA for any tips, even on which regex function I should be using. Mick

1 0

[filesystem] basic_path as parameter
by Alex Lamaison 10 Mar '10

10 Mar '10

I'd like to use basic_path as a function parameter so that it works correctly whether a wide or narrow string is passed. template<typename T> void func(basic_path<T> file) { do thing to file } func("myfile"); func(L"myfile"); However I can't do this because basic_path has a second Traits template parameter which is not itself a template. So I tried the following workaround: template<typename T> struct traits_chooser; template<> struct traits_chooser<char*> { typedef boost::filesystem::path_traits traits; }; template<> struct traits_chooser<wchar_t*> { typedef boost::filesystem::wpath_traits traits; }; template<typename T> void func(basic_path<T, typename traits_chooser<T>::traits> file) {...} But my compiler (MSVC 2005) still can't deduce the parameter type. Does anyone know how I can get this to work? Many thanks. Alex Lamaison

3 4

asio tcp async_read never returns
by Tom Kent 10 Mar '10

10 Mar '10

I am trying to convert some existing code to use boost's asio tcp sockets instead of our current implementation. I am able to get a very similar example (of a chat client/server) from the boost site working, but when I attempt to put the code into my own program it stops working. What I am doing: 1. Start a server process 2. The server process makes an empty socket and uses it to listen (with a tcp::acceptor) for TCP connections on a port (10010 for example) 3. Start a client process 4. Have the client process create a socket connect to the server's port 5. When the server sees a client is connecting, it starts listening for data(with async_read) on the socket and creates another empty socket to listen for another TCP connection on the port 6. When the client sees that the server has connected, it sends 100 bytes of data (with async_write) and waits for the socket to tell it the send is finished...when that happens it prints a message and shuts down 7. When the server gets notified that its has data that has been read, it prints a message and shuts down Obviously, I have greatly trimmed this code down from what I'm trying to implement, this is as small as I could make something that reproduces the problem. I'm running on windows and have a visual studio solution file you can get (http://boost.teeks99.com/BoostConnectionTest.zip) There's some memory leaks, thread safety problems, and such, but that's because I'm taking stuff out of existing code, so don't worry about them. Anyway, here's the files one header with some common stuff, a server, and a client. Connection.hpp: #ifndef CONNECTION_HPP #define CONNECTION_HPP #include <boost/system/error_code.hpp> #include <boost/asio.hpp> #include <boost/bind.hpp> class ConnectionTransfer { public: ConnectionTransfer(char* buffer, unsigned int size) : buffer_(buffer), size_(size) { } virtual ~ConnectionTransfer(void){} char* GetBuffer(){return buffer_;} unsigned int GetSize(){return size_;} virtual void CallbackForFinished() = 0; protected: char* buffer_; unsigned int size_; }; class ConnectionTransferInProgress { public: ConnectionTransferInProgress(ConnectionTransfer* ct): ct_(ct) {} ~ConnectionTransferInProgress(void){} void operator()(const boost::system::error_code& error){Other(error);} void Other(const boost::system::error_code& error){ if(!error) ct_->CallbackForFinished(); } private: ConnectionTransfer* ct_; }; class Connection { public: Connection(boost::asio::io_service& io_service): sock_(io_service) {} ~Connection(void){} void AsyncSend(ConnectionTransfer* ct){ ConnectionTransferInProgress tip(ct); //sock_->async_send(boost::asio::buffer(ct->GetBuffer(), // static_cast<std::size_t>(ct->GetSize())), tip); boost::asio::async_write(sock_, boost::asio::buffer(ct->GetBuffer(), static_cast<std::size_t>(ct->GetSize())), boost::bind( &ConnectionTransferInProgress::Other, tip, boost::asio::placeholders::error)); } void AsyncReceive(ConnectionTransfer* ct){ ConnectionTransferInProgress tip(ct); //sock_->async_receive(boost::asio::buffer(ct->GetBuffer(), // static_cast<std::size_t>(ct->GetSize())), tip); boost::asio::async_read(sock_, boost::asio::buffer(ct->GetBuffer(), static_cast<std::size_t>(ct->GetSize())), boost::bind( &ConnectionTransferInProgress::Other, tip, boost::asio::placeholders::error)); } boost::asio::ip::tcp::socket& GetSocket(){return sock_;} private: boost::asio::ip::tcp::socket sock_; }; #endif //CONNECTION_HPP BoostConnectionClient.cpp: #include "Connection.hpp" #include <boost/asio.hpp> #include <boost/bind.hpp> #include <boost/thread.hpp> #include <iostream> using namespace boost::asio::ip; bool connected; bool gotTransfer; class FakeTransfer : public ConnectionTransfer { public: FakeTransfer(char* buffer, unsigned int size) : ConnectionTransfer(buffer, size) { } void CallbackForFinished() { gotTransfer = true; } }; void ConnectHandler(const boost::system::error_code& error) { if(!error) connected = true; } int main(int argc, char* argv[]) { connected = false; gotTransfer = false; boost::asio::io_service io_service; Connection* conn = new Connection(io_service); tcp::endpoint ep(address::from_string("127.0.0.1"), 10011); conn->GetSocket().async_connect(ep, ConnectHandler); boost::thread t(boost::bind(&boost::asio::io_service::run, &io_service)); while(!connected) { boost::this_thread::sleep(boost::posix_time::millisec(1)); } std::cout << "Connected\n"; char data[100]; FakeTransfer* ft = new FakeTransfer(data, 100); conn->AsyncReceive(ft); while(!gotTransfer) { boost::this_thread::sleep(boost::posix_time::millisec(1)); } std::cout << "Done\n"; return 0; } BoostConnectionServer.cpp: #include "Connection.hpp" #include <boost/asio.hpp> #include <boost/bind.hpp> #include <boost/thread.hpp> #include <iostream> using namespace boost::asio::ip; Connection* conn1; bool conn1Done; bool gotTransfer; Connection* conn2; class FakeAcceptor { public: FakeAcceptor(boost::asio::io_service& io_service, const tcp::endpoint& endpoint) : io_service_(io_service), acceptor_(io_service, endpoint) { conn1 = new Connection(io_service_); acceptor_.async_accept(conn1->GetSocket(), boost::bind(&FakeAcceptor::HandleAccept, this, conn1, boost::asio::placeholders::error)); } void HandleAccept(Connection* conn, const boost::system::error_code& error) { if(conn == conn1) conn1Done = true; conn2 = new Connection(io_service_); acceptor_.async_accept(conn2->GetSocket(), boost::bind(&FakeAcceptor::HandleAccept, this, conn2, boost::asio::placeholders::error)); } boost::asio::io_service& io_service_; tcp::acceptor acceptor_; }; class FakeTransfer : public ConnectionTransfer { public: FakeTransfer(char* buffer, unsigned int size) : ConnectionTransfer(buffer, size) { } void CallbackForFinished() { gotTransfer = true; } }; int main(int argc, char* argv[]) { boost::asio::io_service io_service; conn1Done = false; gotTransfer = false; tcp::endpoint endpoint(tcp::v4(), 10011); FakeAcceptor fa(io_service, endpoint); boost::thread t(boost::bind(&boost::asio::io_service::run, &io_service)); while(!conn1Done) { boost::this_thread::sleep(boost::posix_time::millisec(1)); } std::cout << "Accepted incoming connection\n"; char data[100]; FakeTransfer* ft = new FakeTransfer(data, 100); conn1->AsyncReceive(ft); while(!gotTransfer) { boost::this_thread::sleep(boost::posix_time::millisec(1)); } std::cout << "Success!\n"; return 0; } I've searched around a bit, but haven't had much luck. As far as I can tell, I'm almost exactly matching the sample, so it must be something small that I'm overlooking. Any help is much appreciated! Tom P.S. cross posted to stack overflow: http://stackoverflow.com/questions/2412520/

2 1

problem with gather array
by alev mutlu 09 Mar '10

09 Mar '10

Hi I am trying to scatter some values to workers and then gather them. But I get strange error in gather step. Any suggestions? Below is the code and error file. //mpicxx test-boost.cpp -o test-boost -I /home1/mutlu/boost/include/boost-1_37/ /home1/mutlu/boost/lib/libboost_mpi-gcc41-mt-1_37.a #include <boost/mpi/environment.hpp> #include <boost/mpi/communicator.hpp> #include <boost/mpi/collectives.hpp> #include <boost/thread/mutex.hpp> #include <iostream> #include <vector> #define MASTER 0 namespace mpi = boost::mpi; using namespace std; struct x{ string name; int age; }; int arraySize = 23; void silly_func(int *px, int sz){ for(int i = 0; i < sz; i++) px[i] = 100; } int main(int argc, char* argv[]) { mpi::environment env(argc, argv); mpi::communicator world; int m_mySize, w_mySize, kk,i; int *myValues; vector<int> a; vector<int> aa; for(int i = 0; i < arraySize; i++) a.push_back(i); w_mySize = arraySize / world.size(); if (world.rank() == MASTER){ m_mySize = arraySize / world.size() + arraySize % world.size(); myValues = (int *) malloc(m_mySize); } else{ myValues = (int *) malloc(w_mySize); } if (world.rank() == MASTER) scatter(world, a, myValues, w_mySize, 0); else scatter(world, a, myValues, w_mySize, 0); if (world.rank() == MASTER) // append the remaining elements { for (i = w_mySize * world.size(), kk = 0; i < arraySize; i++, kk++) myValues[w_mySize + kk] = a[w_mySize * world.size() + kk]; } cout << "my rank is " << world.rank() << " and my values are" << endl; if (world.rank() == MASTER) for (int i = 0; i < m_mySize; i++) cout << myValues[i] << endl; if (world.rank() != MASTER) for (int i = 0; i < w_mySize; i++) cout << myValues[i] << endl; if (world.rank() != MASTER) silly_func(myValues, w_mySize); else silly_func(myValues, m_mySize); if (world.rank() == MASTER) gather(world, myValues, m_mySize, aa, 0); else gather(world, myValues, w_mySize, aa, 0); if (world.rank() == MASTER){ cout << "======================="<< endl; for(int i = 0; i < aa.size(); i++) cout << aa[i] << endl; } } and error file is [ceng3:23784] *** Process received signal *** [ceng3:23784] Signal: Segmentation fault (11) [ceng3:23784] Signal code: Address not mapped (1) [ceng3:23784] Failing at address: (nil) [ceng3:23784] [ 0] /lib64/libpthread.so.0 [0x30e100de80] [ceng3:23784] [ 1] /lib64/libc.so.6(memcpy+0x37) [0x30e047a107] [ceng3:23784] [ 2] /usr/mpi/gcc/openmpi-1.2.8/lib64/libmpi.so.0(ompi_ddt_copy_content_same_ddt+0xe8) [0x2b180e3b5618] [ceng3:23784] [ 3] /usr/mpi/gcc/openmpi-1.2.8/lib64/libmpi.so.0(ompi_ddt_sndrcv+0x3f3) [0x2b180e3b3ef3] [ceng3:23784] [ 4] /usr/mpi/gcc/openmpi-1.2.8/lib64/openmpi/mca_coll_basic.so(mca_coll_basic_gather_intra+0xd2) [0x2b18142f20a2] [ceng3:23784] [ 5] /usr/mpi/gcc/openmpi-1.2.8/lib64/libmpi.so.0(PMPI_Gather+0x19b) [0x2b180e3c7ccb] [ceng3:23784] [ 6] test-boost(_ZN5boost3mpi6detail11gather_implIiEEvRKNS0_12communicatorEPKT_iPS6_iN4mpl_5bool_ILb1EEE+0x6b) [0x414b29] [ceng3:23784] [ 7] test-boost(_ZN5boost3mpi6gatherIiEEvRKNS0_12communicatorEPKT_iPS5_i+0x50) [0x414c82] [ceng3:23784] [ 8] test-boost(_ZN5boost3mpi6gatherIiEEvRKNS0_12communicatorEPKT_iRSt6vectorIS5_SaIS5_EEi+0x42) [0x414ce8] [ceng3:23784] [ 9] test-boost(main+0x342) [0x40f62c] [ceng3:23784] [10] /lib64/libc.so.6(__libc_start_main+0xf4) [0x30e041d8b4] [ceng3:23784] [11] test-boost(__gxx_personality_v0+0x141) [0x40f199] [ceng3:23784] *** End of error message *** mpirun noticed that job rank 0 with PID 23784 on node ceng3-ib exited on signal 11 (Segmentation fault).

2 3

[iostreams] State of a filtering stream
by Nicola 09 Mar '10

09 Mar '10

Hi, I have implemented a filtering stream for decompressing bzipped files, which looks as shown at the end of the message. I have tried to use it like this: bz2istream bzippedfile("myfile.bz2"); while (bzippedfile >> data) { // process data } but the program enters an endless loop. The only way I can test for the end of file is with: while (bzippedfile.peek() != EOF) { bzippedfile >> data; // process data } Isn't the first method supposed to work? Is my class missing something? Regards Nicola class bz2istream : public boost::iostreams::filtering_stream<boost::iostreams::input> { public: bz2istream(std::string const& path) : ff_(path.c_str(), std::ios_base::in | std::ios_base::binary) { if (ff_.fail()) { // Here we are not distinguishing failbit from badbit... setstate(std::ios_base::failbit); } else { push(boost::iostreams::bzip2_decompressor()); push(ff_); } } private: std::ifstream ff_; };

1 0

Skipper in rules (Spirit)
by Xavier Pegenaute 09 Mar '10

09 Mar '10

Hi, I am trying to create some rule to parse some words until the end of line. To do it I thought to use a phrase_parser and put in the SkipT parameter something like "space - eol". The problem is that seems the SkipT parameter only accepts the space rule. error: no match for call to ‘.... const boost::spirit::qi::difference<boost::spirit::qi::char_class<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >, boost::spirit::qi::eol_parser> note: candidates are: .... const boost::spirit::qi::char_class<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> > In the classic spirit I know it was possible to define. May be I should change the point of view for this new version? how I should deal with it? Thanks & Regards. Xavi.

2 1

boost serialisation: portable binary format cant cope with -1
by Avi Bahra 09 Mar '10

09 Mar '10

I have a strange bug where on the AIX platform I get: boost::archive exception for TimeStruct : integer cannot be represented for boost version 1.40 on restoring a class(TimeStruct) that has a integer data member of value of -1. Its seems strange that the exception is _only_ raised when restoring the class, and not saving Its missing some symmetry somewhere ? Here is the stack trace: //boost::serialization::throw_exception<portable_binary_iarchive_exception>, //portable_binary_iarchive::load_impl, //portable_binary_iarchive::load<int>, //boost::archive::load_access::load_primitive<portable_binary_iarchive,int>, //boost::archive::detail::load_non_pointer_type<portable_binary_iarchive,int>::load_primitive::invoke, //boost::archive::detail::load_non_pointer_type<portable_binary_iarchive,int>::invoke, //boost::archive::load<portable_binary_iarchive,int>, //boost::archive::detail::common_iarchive<portable_binary_iarchive>::load_override<int>, //portable_binary_iarchive::load_override<int>, //boost::archive::detail::interface_iarchive<portable_binary_iarchive>::operator >><int>, //boost::archive::detail::interface_iarchive<portable_binary_iarchive>::operator &<int>, //TimeStruct::serialize<portable_binary_iarchive>, // ..... This is raised in: void portable_binary_iarchive::load_impl(boost::intmax_t & l, char maxsize){ char size; l = 0; this->primitive_base_t::load(size); if(0 == size){ return; } bool negative = (size < 0); if(negative) size = -size; if(size > maxsize) boost::serialization::throw_exception( portable_binary_iarchive_exception() ); ..... The exception is raised because size=255 and maxsize=4 ? Here is the example which produces the exception: Please note that you will have to dig out and compile the portable binary archives out of the boost serialisation examples dirs. //================ Main.cpp ========================= // This example demonstrates a possible bug in // portable binary format on AIX when serialising -1 // that is specific only to the AIX compiler/platform // (i.e HPUX/Acc and linux/gcc run without any problems) // However on AIX on the restore I get: // boost::archive exception for TimeStruct : integer cannot be represented // // This test consists of 1 files // 1/ Main.cpp // #include <sstream> #include <ostream> #include <iostream> #include <fstream> #include <boost/archive/binary_oarchive.hpp> #include <boost/archive/binary_iarchive.hpp> #include <boost/archive/text_iarchive.hpp> #include <boost/archive/text_oarchive.hpp> #include "portable_binary_oarchive.hpp" #include "portable_binary_iarchive.hpp" #include <boost/serialization/serialization.hpp> using namespace std; class TimeStruct { public: TimeStruct() : hour_(-1), minute_(-1) {} TimeStruct(int hour, int min) : hour_(hour), minute_(min) {} bool operator==(const TimeStruct& rhs) const { return ((hour_ == rhs.hour_) && (minute_ == rhs.minute_));} bool operator!=(const TimeStruct& rhs) const { return !operator==(rhs);} int hour() const { return hour_;} int minute() const { return minute_;} bool isNULL() const { return (hour_ == -1) || (minute_ == -1); } // returns struct in the format hh:mm std::string toString() const { std::stringstream ss; if (hour_ == -1) ss << hour_; else if (hour_ < 10) ss << "0" << hour_; else ss << hour_; ss << ":"; if (minute_ == -1) ss << minute_; else if (minute_ < 10) ss << "0" << minute_; else ss << minute_; return ss.str(); } private: int hour_; int minute_; friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int /*version*/) { ar & hour_; ar & minute_; } }; bool compare(const TimeStruct& lhs, const TimeStruct& rhs) { if (lhs.isNULL() && rhs.isNULL()) return true; if (lhs.isNULL() && !rhs.isNULL()) return false; if (!lhs.isNULL() && rhs.isNULL()) return false; if (lhs.hour() != rhs.hour()) return false; if (lhs.minute() != rhs.minute()) return false; return true; }; static void save(const std::string& fileName, const TimeStruct& ts, bool textArchive); static void restore(const std::string& fileName, TimeStruct& ts, bool textArchive); int main() { { TimeStruct saved; save("fred.txt",saved,true); TimeStruct restored; restore("fred.txt",restored,true); assert(saved == restored); } { TimeStruct saved; save("fred.txt",saved,false); TimeStruct restored; restore("fred.txt",restored,false); assert(saved == restored); } return 0; } void save(const std::string& fileName, const TimeStruct& ts, bool textArchive) { if ( textArchive ) std::cout << "Text archive Saving " << ts.toString(); else std::cout << "portable binary archive Saving " << ts.toString(); try { if (textArchive) { std::ofstream ofs( "fred.txt" ); boost::archive::text_oarchive ar( ofs ); ar << ts; } else { std::ofstream ofs( fileName.c_str(), ios::binary ); portable_binary_oarchive ar(ofs); ar << ts; } std::cout << " OK \n"; } catch (const boost::archive::archive_exception& ae) { std::cout << " save " << fileName << " failed. boost::archive exception for TimeStruct " << ": " << ae.what() << std::endl; } } void restore(const std::string& fileName, TimeStruct& restored, bool textArchive) { if ( textArchive ) std::cout << "Text archive Restoring "; else std::cout << "portable binary archive Restoring " ; try { if ( textArchive ) { std::ifstream ifs( fileName.c_str() ); boost::archive::text_iarchive ar( ifs ); ar >> restored; } else { std::ifstream ifs( fileName.c_str(), ios::binary ); portable_binary_iarchive ar( ifs ); ar >> restored; } std::cout << restored.toString() << " OK \n"; } catch ( const boost::archive::archive_exception& ae ) { std::cout << " restore " << fileName << " failed. boost::archive exception for TimeStruct " << ": " << ae.what() << std::endl; } } Best regards, Ta, Avi

1 0

[Boost.Log] Did I miss the formal review start mail?
by Roland Bock 09 Mar '10

09 Mar '10

Hi, a week ago, Vladimir wrote that a formal review of boost.log would start this week. Did I miss the formal mail? Thanks and regards, Roland

4 6

[filesystem] basic_path as parameter
by Alexander Lamaison 09 Mar '10

09 Mar '10

I'd like to use basic_path as a function parameter so that it works correctly whether a wide or narrow string is passed. template<typename T> void func(basic_path<T> file) { do thing to file } func("myfile"); func(L"myfile"); However I can't do this because basic_path has a second Traits template parameter which is not itself a template. So I tried the following workaround: template<typename T> struct traits_chooser; template<> struct traits_chooser<char*> { typedef boost::filesystem::path_traits traits; }; template<> struct traits_chooser<wchar_t*> { typedef boost::filesystem::wpath_traits traits; }; template<typename T> void func(basic_path<T, typename traits_chooser<T>::traits> file) {...} But my compiler (MSVC 2005) still can't deduce the parameter type. Does anyone know how I can get this to work? Many thanks. Alex Lamaison

1 0

[boost::asio] exception not passed to async callback
by Matheus Araújo Aguiar 09 Mar '10

09 Mar '10

Hello list, Right now i am having some problems with a TCP socket waiting for a pending async read operation. When the remote endpoint closes the connection due to some crash or other unexpected situation(i.e, without proper closing of the socket) my application is terminated with this message: "Terminate called after throwing an instance of 'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::system::system_error> >' what(): Transport endpoint is not connected Aborted" Maybe i am missing something here, because i expected any boost::system exceptions to be passed to the callback associated with the async read operation. I am assuming that this exception is thrown in the io_service::run method, is that right? If so, why it is not passed to the callback? and what can i do to catch it, having the io_service::run running on a separeted thread? Thanx in advance and best regards, -- Matheus Araújo Aguiar Computer Scientist matheus.pit(a)gmail.com

2 2

Boost.Random question
by gast128 09 Mar '10

09 Mar '10

Hello all, a colleague of my asked me to drop a question on the forum about the following case: He produces 1000 samples with the following code: boost::normal_distribution<double> n1(1, sqrt(4.0)); boost::variate_generator< boost::minstd_rand, boost::normal_distribution<double> > g1(boost::minstd_rand(), n1); He also calulates the covariance. It should be something like (4 0) but he got (4.1 8.3). This 4 is correct, but the 8.3 not. Anyone an idea? Note (again): post from a colleague; i didn't try it myself.

2 2

Boost.Asio tcp::acceptor after close, then open->listen got error!!!!
by l.jay Yuan 09 Mar '10

09 Mar '10

Boost.Asio tcp::acceptor after close, then open->listen got error!!!! cannot reopen?

2 2

[filesystem] basic_path as paramter
by Alexander Lamaison 09 Mar '10

09 Mar '10

I'd like to use basic_path as a function parameter so that it works correctly whether a wide or narrow string is passed. template<typename T> void func(basic_path<T> file) { do thing to file } func("myfile"); func(L"myfile"); However I can't do this becuase basic_path has a second Traits template paramter which is not itself a template. So I tried the following workaround: template<typename T> struct traits_chooser; template<> struct traits_chooser<char*> { typedef boost::filesystem::path_traits traits; }; template<> struct traits_chooser<wchar_t*> { typedef boost::filesystem::wpath_traits traits; }; template<typename T> void func(basic_path<T, typename traits_chooser<T>::traits> file) {...} But my compiler (MSVC 2005) still can't deduce the paramter type. Does anyone know how I can get this to work? Many thanks. Alex Lamaison

1 0

BOOST_ALL_DYN_LINK
by Paul 09 Mar '10

09 Mar '10

Hi all, I'm confused about boost dynamic linking on windows MSVC90 I always define: BOOST_ALL_NO_LIB So that I directly control which DLLs I link to. I add the signals dll for linking. Then, if I define BOOST_ALL_DYN_LINK, I get lots of these messages: boost_1_42_0\boost/signals/detail/signal_base.hpp(113) : warning C4251: 'boost::signals::detail::signal_base_impl::combiner_' : class 'boost::any' needs to have dll-interface to be used by clients of class 'boost::signals::detail::signal_base_impl' 39> boost_1_42_0\boost/any.hpp(36) : see declaration of 'boost::any' I've read up on this and understand why the warnings are shown. BUT, I don't understand why I am able to still link my program if I do NOT define BOOST_ALL_DYN_LINK. Without the flag, it compiles without warnings, it links without problems, AND the executable requires the signals DLL to be available, so clearly it IS dynamically linked. Right? Any ideas? Thanks, Paul

4 4

[serialization] Sets of shared pointers won't load
by John Pallister 09 Mar '10

09 Mar '10

Hello list, I'm using Visual C++ Express 2008 and Boost 1.42. I have a graph of classes I'm trying to serialise, and I'm using shared_ptrs to manage multiple references to the same object, but I can't deserialise my graph corectly. I get errors like: First-chance exception at 0x7c812afb in sams-6.exe: Microsoft C++ exception: std::basic_string<char,std::char_traits<char>,std::allocator<char> > at memory location 0x03d7f28c.. HEAP[sams-6.exe]: Invalid allocation size - AC1051B4 (exceeded 7ffdefff) First-chance exception at 0x7c812afb in sams-6.exe: Microsoft C++ exception: std::bad_alloc at memory location 0x03c7dc5c.. HEAP[sams-6.exe]: Invalid allocation size - AC1051A8 (exceeded 7ffdefff) Here are my classes: struct stats_t { friend class boost::serialization::access; typedef int ts_t; size_t bytes, packets; ts_t firstPacketTs, lastPacketTs; stats_t() : bytes(0), packets(0), firstPacketTs(0), lastPacketTs(0) { } private: template<class Archive> void serialize(Archive &ar, unsigned int /* file_version */) { ar & bytes & packets & firstPacketTs & lastPacketTs; } }; struct dest_port_t { friend class boost::serialization::access; endpoint_t endpoint; shp_socket_t socket; bool inUse; stats_t stats; std::string name; boost::asio::ip::udp::endpoint baue; dest_port_t(const endpoint_t &e, const std::string &n=std::string()) : endpoint(e), inUse(false), name(n), baue(boost::asio::ip::address_v4(e.first), e.second) { } private: template<class Archive> void serialize(Archive &ar, unsigned int /* file_version */) { ar & endpoint & name & inUse & stats; } }; typedef boost::shared_ptr<dest_port_t> shp_dest_port_t; typedef std::set<shp_dest_port_t> dest_port_shpset_t; BOOST_SERIALIZATION_SHARED_PTR( dest_port_t ) namespace boost { namespace serialization { template<class Archive> inline void load_construct_data(Archive &ar, dest_port_t *dpp, unsigned int /* file_version */) { endpoint_t endpoint; std::string name; ar >> endpoint; ar >> name; ::new(dpp) dest_port_t(endpoint, name); ar >> dpp->inUse; ar >> dpp->stats; } } } struct dest_t { friend class boost::serialization::access; endpoint_t endpoint; dest_port_shpset_t ports; size_t connections; std::string name; dest_t(const endpoint_t &e=endpoint_t(), const std::string &n=std::string()) : endpoint(e), connections(0), name(n) { } private: template<class Archive> void serialize(Archive &ar, unsigned int /* file_version */) { ar & endpoint & ports & connections & name; } }; typedef boost::shared_ptr<dest_t> shp_dest_t; typedef std::set<shp_dest_t> dest_shpset_t; BOOST_SERIALIZATION_SHARED_PTR( dest_t ) struct source_t { friend class boost::serialization::access; endpoint_t endpoint; size_t connections; stats_t stats; const bool foreign; // True for 'unrecognised' sources. std::string name; source_t(const endpoint_t &e=endpoint_t(), bool f=false, const std::string &n=std::string()) : endpoint(e), connections(0), foreign(f), name(n) { } private: template<class Archive> void serialize(Archive &ar, unsigned int /* file_version */) { ar & endpoint & connections & stats & const_cast<bool &>(foreign) & name; } }; typedef boost::shared_ptr<source_t> shp_source_t; typedef std::set<shp_source_t> source_shpset_t; BOOST_SERIALIZATION_SHARED_PTR( source_t ) struct connection_t { friend class boost::serialization::access; shp_source_t source; shp_dest_port_t dest_port; shp_dest_t dest; stats_t stats; connection_t(const shp_source_t &s, const shp_dest_port_t &dp, const shp_dest_t &d=shp_dest_t()) : source(s), dest_port(dp), dest(d) { } private: template<class Archive> void serialize(Archive &ar, unsigned int /* file_version */) { ar & source & dest_port & dest & stats; } }; typedef std::set<connection_t> connection_set_t; typedef std::map<endpoint_t, connection_set_t> talkspurt_map_t; namespace boost { namespace serialization { template<class Archive> inline void load_construct_data(Archive &ar, connection_t *cp, unsigned int /* file_version */) { shp_source_t src; shp_dest_port_t dest_port; shp_dest_t dest; ar >> src; ar >> dest_port; ar >> dest; ::new(cp) connection_t(src, dest_port, dest); ar >> cp->stats; } } } class UdpWorker : public syn::Thread { protected: size_t errors_; stats_t total_, invalid_, ignored_; dest_shpset_t dests_; source_shpset_t sources_; talkspurt_map_t talkspurtMap_; }; So it's UdpWorker -> dest_shpset_t -> dest_t -> dest_port_shpset_t -> stats_t, UdpWorker -> source_shpset_t -> source_t -> stats_t, UdpWorker -> talkspurt_map_t -> connection_set_t -> shp_source_t etc. The code to save is: void UdpWorker::save() { try { ofstream os(stateFile_.c_str()); boost::archive::text_oarchive oa(os); oa << errors_; oa << total_; oa << invalid_; oa << ignored_; oa << sources_; oa << dests_; oa << talkspurtMap_; } catch (boost::archive::archive_exception &ae) { log("UdpWorker::save(): Error - caught archive_exception \"%s\" while saving to text archive \"%s\".", ae.what(), stateFile_.c_str()); } catch (...) { log("UdpWorker::save(): Error - caught unknown exception while saving to text archive \"%s\".", stateFile_.c_str()); } } And the loading code is very similar: void UdpWorker::load() { try { ifstream is(stateFile_.c_str()); boost::archive::text_iarchive ia(is); ia >> errors_; ia >> total_; ia >> invalid_; ia >> ignored_; ia >> sources_; ia >> dests_; ia >> talkspurtMap_; } catch (boost::archive::archive_exception &ae) { log("UdpWorker::load(): Error - caught archive_exception \"%s\" while loading from text archive \"%s\".", ae.what(), stateFile_.c_str()); } catch (...) { log("UdpWorker::load(): Error - caught unknown exception while loading from text archive \"%s\".", stateFile_.c_str()); } } The archive seems to be written OK, but when loading it seems to load the sources_ set OK and then die on the dests_ set, with the bad_alloc exceptions given above. So the talkspurt_map_t hasn't been tested yet... I've tried the binary archive, but I get pretty much the same error. I'd really appreciate it if someone with a more experienced eye could have a look at my classes and tell me if there's anything suspicious. Is BOOST_SERIALIZATION_SHARED_PTR still required in 1.42? I couldn't find any mention of it in the documentation, but many examples seem to use it. It looks like it's a no-op anyway on this compiler. Thanks very much, John :^P -- John Pallister john(a)johnp.net john(a)synchromesh.com

1 0

Using Boost.Atomic for thread-safe reference counting with strong exception guarantee
by Narcoleptic Electron 08 Mar '10

08 Mar '10

I'm trying to create a thread-safe, strong-exception-guaranteed "intrusive_pte" (intrusive pointee) class that represents a drop-in reference-counted base class for a pointee of intrusive_ptr. I'm using the pending Boost.Atomic library (http://www.chaoticmind.net/~hcb/projects/boost.atomic/) and am basing my code on the example given (http://www.chaoticmind.net/~hcb/projects/boost.atomic/doc/atomic/usage_exam…) but not yet having a sound understanding of memory barriers, I am unsure if my code for the overflow exception is correct or ideal. The relevant code snippet is below. Any feedback would be greatly appreciated. Thanks! --- mutable atomic< IntegralType > ref_count; mutable mutex add_ref_mutex; void add_ref() const { mutex::scoped_lock add_ref_lock( add_ref_mutex ); if ( integer_traits< IntegralType >::const_max == ref_count.load( memory_order_relaxed ) ) { throw_exception( std::overflow_error( "Reference count overflow." ) ); } ref_count.fetch_add( 1, memory_order_relaxed ); } friend void intrusive_ptr_add_ref ( intrusive_pte const * const p ) { BOOST_ASSERT( p && "The argument cannot be null." ); p->add_ref(); } friend void intrusive_ptr_release ( intrusive_pte * const p ) { BOOST_ASSERT( p && "The argument cannot be null." ); BOOST_ASSERT( ( 0 < p->ref_count.load( memory_order_acquire ) ) && "Reference count underflow." ); if ( p->ref_count.fetch_sub( 1, memory_order_release ) == 1 ) { atomic_thread_fence( memory_order_acquire ); checked_delete( p ); } }

1 0

[Serialization] Strange giant warning
by David 08 Mar '10

08 Mar '10

For a short while now I've been using boost serialization. It works perfectly... except... it keeps coming up one massive warning (that takes up ~100 lines). (see below) Whenever I get annoyed, I try to experiment and then search for answers online, but no luck. I'm probably using the library incorrectly somewhere. So I made a small program that generates the problem. Any advice on what I could be doing wrong would be appreciated. I use vc++ 2008 btw. Thanks. Code: -------------------------------------------- /* demonstration of problem. The program asks the user for a number, and then saves this number to a file. When the user returns, the number is remembered. */ #include <iostream> #include <fstream> #include <boost/serialization/shared_ptr.hpp> #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> // save and load methods void save (const char * fname); bool load (const char * fname); // returns if successful // I know this is way too simple to put in a class, but bare with me class Game { public: Game () { number = 0; } void getNumberFromUser () { std::cin >> number; } int getNumber () { return number; } private: int number; friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & number; } }; typedef boost::shared_ptr< Game > Game_ptr; Game_ptr game; // entry int main () { game = Game_ptr( new Game ); // welcome std::cout << "Hello\n"; // if file exists, recall the number if (load ("save.txt")) std::cout << "You're number is " << game->getNumber() << ".\n"; // ask user for number std::cout << "Enter a number: \n"; game->getNumberFromUser (); // memorise number save ("save.txt"); // exit return 0; } void save (const char * fname) { std::ofstream ofs( fname ); boost::archive::text_oarchive oa( ofs ); // save oa << game; } bool load (const char * fname) { std::ifstream ifs( fname ); if (!ifs) return false; // file doesn't already exist boost::archive::text_iarchive ia( ifs ); // load ia >> game; // <------ Removing this line makes the warning go away return true; } Warning: -------------------------------------------- 1>main.cpp 1>d:\dev\boostpro\boost\boost_1_40\boost\serialization\extended_type_info_typeid.hpp(88) : warning C4099: 'boost::serialization::static_warning_impl<false>::STATIC_WARNING' : type name first seen using 'struct' now seen using 'class' 1> d:\dev\boostpro\boost\boost_1_40\boost\serialization\static_warning.hpp(115) : see declaration of 'boost::serialization::static_warning_impl<false>::STATIC_WARNING' 1> d:\dev\boostpro\boost\boost_1_40\boost\serialization\extended_type_info_typeid.hpp(85) : while compiling class template member function 'const boost::serialization::extended_type_info *boost::serialization::extended_type_info_typeid<T>::get_derived_extended_type_info(const T &) const' 1> with 1> [ 1> T=Game 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\archive\shared_ptr_helper.hpp(105) : see reference to class template instantiation 'boost::serialization::extended_type_info_typeid<T>' being compiled 1> with 1> [ 1> T=Game 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\serialization\shared_ptr.hpp(138) : see reference to function template instantiation 'void boost::archive::detail::shared_ptr_helper::reset<Game>(boost::shared_ptr<T> &,T *)' being compiled 1> with 1> [ 1> T=Game 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\serialization\split_free.hpp(58) : see reference to function template instantiation 'void boost::serialization::load<Archive,Game>(Archive &,boost::shared_ptr<T> &,const unsigned int)' being compiled 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\serialization\split_free.hpp(54) : while compiling class template member function 'void boost::serialization::free_loader<Archive,T>::invoke(Archive &,T &,const unsigned int)' 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=boost::shared_ptr<Game> 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\serialization\split_free.hpp(74) : see reference to class template instantiation 'boost::serialization::free_loader<Archive,T>' being compiled 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=boost::shared_ptr<Game> 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\serialization\shared_ptr.hpp(153) : see reference to function template instantiation 'void boost::serialization::split_free<Archive,boost::shared_ptr<T>>(Archive &,boost::shared_ptr<T> &,const unsigned int)' being compiled 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\serialization\serialization.hpp(133) : see reference to function template instantiation 'void boost::serialization::serialize<Archive,Game>(Archive &,boost::shared_ptr<T> &,const unsigned int)' being compiled 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\archive\detail\iserializer.hpp(174) : see reference to function template instantiation 'void boost::serialization::serialize_adl<Archive,T>(Archive &,T &,const unsigned int)' being compiled 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game_ptr 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\archive\detail\iserializer.hpp(161) : while compiling class template member function 'void boost::archive::detail::iserializer<Archive,T>::load_object_data(boost::archive::detail::basic_iarchive &,void *,const unsigned int) const' 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game_ptr 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\archive\detail\iserializer.hpp(362) : see reference to class template instantiation 'boost::archive::detail::iserializer<Archive,T>' being compiled 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game_ptr 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\archive\detail\iserializer.hpp(351) : while compiling class template member function 'void boost::archive::detail::load_non_pointer_type<Archive,T>::load_standard::invoke(Archive &,T &)' 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game_ptr 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\archive\detail\iserializer.hpp(417) : see reference to class template instantiation 'boost::archive::detail::load_non_pointer_type<Archive,T>::load_standard' being compiled 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game_ptr 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\archive\detail\iserializer.hpp(405) : while compiling class template member function 'void boost::archive::detail::load_non_pointer_type<Archive,T>::invoke(Archive &,T &)' 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game_ptr 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\archive\detail\iserializer.hpp(542) : see reference to class template instantiation 'boost::archive::detail::load_non_pointer_type<Archive,T>' being compiled 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game_ptr 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\archive\detail\common_iarchive.hpp(61) : see reference to function template instantiation 'void boost::archive::load<Archive,T>(Archive &,T &)' being compiled 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game_ptr 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\archive\basic_text_iarchive.hpp(62) : see reference to function template instantiation 'void boost::archive::detail::common_iarchive<Archive>::load_override<T>(T &,int)' being compiled 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game_ptr 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\archive\text_iarchive.hpp(66) : see reference to function template instantiation 'void boost::archive::basic_text_iarchive<Archive>::load_override<T>(T &,int)' being compiled 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game_ptr 1> ] 1> d:\dev\boostpro\boost\boost_1_40\boost\archive\detail\interface_iarchive.hpp(61) : see reference to function template instantiation 'void boost::archive::text_iarchive_impl<Archive>::load_override<T>(T &,int)' being compiled 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game_ptr 1> ] 1> d:\dev\visual studio 2008\projects\boostserialisation\boostserialisation\main.cpp(82) : see reference to function template instantiation 'Archive &boost::archive::detail::interface_iarchive<Archive>::operator >><Game_ptr>(T &)' being compiled 1> with 1> [ 1> Archive=boost::archive::text_iarchive, 1> T=Game_ptr 1> ]

3 4

[graph][spirit] Boost.Graph and Boost.Spirit incompatible ?
by Maxime van Noppen 08 Mar '10

08 Mar '10

Hi, After my very big disappointment when I discovered that Boost.Graph and Boost.Variant where incompatible[1], now it seems that Boost.Graph and Boost.Spirit (and more precisely Qi) are incompatible... :( Minimal test case : -------- test.cc ----------- #include <boost/graph/dijkstra_shortest_paths.hpp> #include <boost/spirit/include/qi.hpp> ---------------------------- > $ g++ -c test.cc > In file included from /usr/include/boost/graph/properties.hpp:19, > from /usr/include/boost/graph/named_function_params.hpp:13, > from /usr/include/boost/graph/dijkstra_shortest_paths.hpp:20, > from inc_test.cc:1: > /usr/include/boost/property_map/property_map.hpp: In instantiation of ‘boost::property_traits<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >’: > /usr/include/boost/graph/two_bit_color_map.hpp:47: instantiated from ‘boost::two_bit_color_map<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >’ > /usr/include/boost/spirit/home/qi/char/char.hpp:206: instantiated from here > /usr/include/boost/property_map/property_map.hpp:31: error: no type named ‘key_type’ in ‘struct std::basic_string<char, std::char_traits<char>, std::allocator<char> >’ > /usr/include/boost/property_map/property_map.hpp:34: error: no type named ‘category’ in ‘struct std::basic_string<char, std::char_traits<char>, std::allocator<char> >’ > /usr/include/boost/property_map/property_map.hpp: In instantiation of ‘boost::property_traits<std::list<boost::spirit::info, std::allocator<boost::spirit::info> > >’: > /usr/include/boost/graph/two_bit_color_map.hpp:47: instantiated from ‘boost::two_bit_color_map<std::list<boost::spirit::info, std::allocator<boost::spirit::info> > >’ > /usr/include/boost/spirit/home/support/detail/what_function.hpp:35: instantiated from here > /usr/include/boost/property_map/property_map.hpp:31: error: no type named ‘key_type’ in ‘class std::list<boost::spirit::info, std::allocator<boost::spirit::info> >’ > /usr/include/boost/property_map/property_map.hpp:34: error: no type named ‘category’ in ‘class std::list<boost::spirit::info, std::allocator<boost::spirit::info> >’ I have g++ 4.4.3 on Linux amd64 and Boost 1.42.0. Maybe there should be some documentation about such incompatibilities between boost libraries. [1] http://lists.boost.org/boost-users/2010/01/55317.php -- Maxime

4 21

[Review] ITL review starts today, February 18th
by Hartmut Kaiser 08 Mar '10

08 Mar '10

Hi all, The formal review of the Interval Template Library (ITL) starts today, February 18th, 2010 and will end February 27th, 2010. ITL is being developed by Joachim Faulhaber. ------------------------------------------------ About the library: The Interval Template Library (ITL) is a library of interval containers that facilitates computations on collections of intervals and associated values. Use cases of such computations typically occur in the date and time problem domain, when collections of time intervals with associated data are analyzed, combined and aggregated. But the scope of applications for interval containers is more general and not limited to date and time problems. Interval containers allow to access and manipulate collections of intervals on an abstract level as sets and maps (of elements), but also to exploit segmental information that is given by the interval borders. Interval containers are fairly generic. They can be instantiated with discrete domain (or key) types like integral numeric types or boost::date or time types. But they also work with continuous domain types like double, rational or string. Using the latter allows to represent infinite sets and maps. The interface of the interval containers strives to be very intuitive and in line with the stl and other boost libraries. * The set theoretic operations union, difference, intersection and symmetric difference are available as operators for all interval containers and for many useful overloads between them. * There is iterator support on the level of segments and interval containers can be combined with stl containers of intervals via stl algorithms. * For discrete domain types, element iterators are available which makes interval sets and maps models of SortedAssociative Containers so they can be used with many stl algorithms. All interval containers are addable and subtractable. The addability and subtractability concept of the ITL leads to a general mechanism of aggregation on interval_maps which is called 'aggregate on overlap'. Exploiting 'aggregate on overlap' allows to compute many useful aggregation results in a simple and abstract manner. The ITL's Set and Map concepts are defined by a signature and collections of laws or axioms. Those semantical constraints have been validated using automatic law based tests. This gives the library both a well founded formal specification and an unusual thorough test base. The ITL emerged out of real world use cases and is successfully used at Cortex Software GmbH since a couple of years in the production code of various applications. On the boost developer's list it has been proposed in four previews and a review request since May 2008 and has been refactored and refined according to boost standards and suggestions from the list. The ITL is available from the boost vault: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=itl_3_2 _0.zip&directory=Containers Documentation is online available at: http://www.herold-faulhaber.de/boost_itl/doc/libs/itl/doc/html/index.html The current sources are in the sandbox: https://svn.boost.org/svn/boost/sandbox/itl/ ------------------------------------------------ Everybody on this list is invited to participate in this formal review. I hope to see your review of this library, including your vote, and I welcome your participation in the discussions on the Boost mailing list. Please always state in your review, whether you think the library should be accepted as a Boost library. Additionally, please consider giving feedback on the following general topics: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? Regards Hartmut Review Manager --------------- Meet me at BoostCon www.boostcon.com

5 5

Random number generation
by David Kaplan 08 Mar '10

08 Mar '10

I'm using the following code to generate a random 64 bit value: boost::mt19937 rng; boost::uniform_int<uint64_t> r(0,0xffffffffffffffff); boost::variate_generator<boost::mt19937&, boost::uniform_int<uint64_t> > gen(rng, r); uint64_t id = gen(); However it seems it's not random on each execution of the program? (rather I get the same value again). How do I randomise this properly?

3 4

how to share information about a open socket?
by pedro chaparro 08 Mar '10

08 Mar '10

Hi, based on the example http://www.boost.org/doc/libs/1_42_0/doc/html/boost_asio/tutorial/tutdaytim…, i wanna to separate the part of the code that open de connection , and the part of the code that write a string over the socket, the problem is , that i have no clear how to share the information of the socket between the both fuctions. In this code below i suppose that listen fucion must to return the socket information, but what data type must the function listen() return??? thanks so much in advance void Agent::listen() { try { printf("SERVER A STARTED UDPsk \n"); boost::asio::io_service io_service; tcp::acceptor acceptor(io_service, tcp::endpoint(tcp::v4(), 7777)); //for (;;) { tcp::socket socket(io_service); acceptor.accept(socket); } } catch (std::exception& e) { std::cerr << e.what() << std::endl; } } void Agent::write() { try { std::string message = "mymsg"; boost::system::error_code ignored_error; boost::asio::write(socket, boost::asio::buffer(message), boost::asio::transfer_all(), ignored_error); sleep(1); socket.close(); return; } } catch (std::exception& e) { std::cerr << e.what() << std::endl; } } -- Ing Pedro Alonso Chaparro Valero Ciudad Politecnica de la Innovación iTEAM - Mobile Communications Group Polytechnic University of Valencia C\ Camino de Vera S/N, Edificio 8G 46022 Valencia, Spain

3 2

[Review] The review of the ITL library ends today, March 7th
by Hartmut Kaiser 08 Mar '10

08 Mar '10

Hey all, The review of Joachim Faulhabers ITL library ends today, March 7th 2010. Please get your reviews in today or get in contact with me to agree on some offline schedule. Regards Hartmut Review Manager --------------- Meet me at BoostCon www.boostcon.com

4 4

[range] Best way to construct a std::set from a range?
by Gabriel Redner 08 Mar '10

08 Mar '10

If I have a pair of iterators, I can construct a set like so: std::set<SomeType> s(it1, it2); If instead I have a range, I can adapt it like so: std::set<SomeType> s(boost::begin(range), boost::end(range)); However, my range object is being constructed on the fly. I'd like to be able to do: std::set<SomeType> s(MakeRange(args)); But clearly this is not supported by the library. It seems I need to store the range object in a variable in order to do this, which defeats the syntax-simplifying benefits of using ranges. Can this be avoided? Are there some recommended no-overhead tricks for doing this that achieve a clean syntax? Implicit conversions? Explicit "ToSet" conversion functions? Can boost.assign be of help? (My initial reading of the assign documentation suggests not, but perhaps I'm missing something). I'm also not averse to a macro so long as it looks "language-like," but so far I haven't produced anything satisfactory. Has anyone else wrestled with this one and come out victorious? Thanks, -Gabe

6 7

[mpi] open/write to file for simple output
by alfC 07 Mar '10

07 Mar '10

Hi, I am fairly new to mpi (and boost mpi). I have an mpi program and I need to dump some intermediate and results to a simple text file. First, is there already any good (using boost.mpi or not) to open and write files (let's say from process 0) and write to them. Second, if not, I am already trying to make the code as transparent as possible: I guess the most primitive way to do this is to do something like ofstream ofs(); if(world.rank()==0) ofs.open("file"); ... if(world.rank()==0) ofs<<result<<endl; but the code is full of "if(world.rank()==0)" and worst of all there is a dangling ofs. I tried other possibilities, like making intensive use of boost::optional boost::optional<std::ofstream> optional_ofs(world.rank()==0, std::ofstream("file") ); ... if(optional_ofs) *optional_ofs<<result<<endl; //or optional_ofs? *optional_ofs<<result<<endl; and even activating exceptions for boost optional, in such a way that this makes sense: try{ *optional_ofs<<result<<endl; }catch(...){} and executes only for the process(es) where the stream is actually created. The good thing is that once the stream is created it handles its own existence, regardless of the process number chosen to write to the file. I also looked into boost.interprocess file_lock but it seems it doesn't apply to this case. The third option is more complicated (although I partially implemented it already) by encapsulating this in a class such that the following syntax makes sense for the parallel execution mpi::ofstream ofs("file", world); // class mpi::ofstream is defined somehow, only one process actually opens the file ofs<<result<<endl; //(indirectly only the first process writes to the file This is even more general because (optionally) I can make the result to be printed only once if all processes agree in the results (the value of the variable is common) or different times (or just fail) if the actaul values of result do not agree from all the processes. does this all makes any sense? or I am reinventing the wheel? Also, in my particular cluster, all the processes share the same file system, which I think it is the common case but also the origin of the dilemma. (Note that I am *not* trying to write a file in parallel, I am just trying to print common (gathered) results to a file. nor I am trying to read from a file for the moment) Any advice? Thank you, Alfredo

2 1

Graph Library Random Access Iterators?
by Theodore McCormack 06 Mar '10

06 Mar '10

Hello all, I am trying to iterate through a list of edges in the boost graph library, but i would like to advance more than one at a time or be able to use random access to an edge in the set. For example: Currently, to find the edge at index in the edge set I have to iterate through all the edges: Edge e; int count = 0; for (edge_range_t er = edges(graph); er.first != er.second; er.first++) { e = (*er.first); if (count == index) break; count++; } return e; I would like something like: Edge e; edge_range_t er = edges(graph); e = (*er[index].first); return e; Is there a way to index with iterators? Regards

3 7

[boost-users][git] gitting boost
by Andrey Torba 06 Mar '10

06 Mar '10

Hi all, I prefer git over svn. I use a git clone of boost: origin git://sodium.resophonic.com/boost It had worked perfectly until several months ago it started to return the error on 'git pull' command: fatal: The remote end hung up unexpectedly The same error occurs if i clone git://gitorious.org/boost/svn.git. I use git version 1.6.3.3. How can i git boost? Thanks -- Regards, Andrey

1 0

[program_option] how to say only certain strings are allowed as arguments?
by Thorsten Ottosen 06 Mar '10

06 Mar '10

Hi, Is there some way to say bpo::options_description desc("Allowed options"); desc.add_options() ("method", bpo::value<std::string>()->allowed_values("foo")("bar"), "" ) so I donøt have to reject the arguments manually? Thanks -Thorsten

4 4

[proto] Deep copy question
by Manjunath Kudlur 06 Mar '10

06 Mar '10

Hello, I define the copy constructor for my class and print out out a message when it is called. See the following program. When I have "proto::terminal<Var<int> >::type a", and try to call BOOST_PROTO_AUTO(pr, a), I see that the copy constructor is called two times. Why is the object getting copied twice during the deep copy? When I have "proto::literal<Var<int> > a", I see that the copy constructor is getting called twice during the declaration of 'a' itself, and twice when I try to call BOOST_PROTO_AUTO(pr, a). I was under the impression that objects are held by reference inside expressions. Why are they copied twice in the proto::literal case? Actually, I am looking for some advice on the following: I know that when I have proto::terminal<Var<int> >, the underlying object is created once, and held by reference *everywhere* it is appears in a large complex expression. But as soon as I try to do a deep_copy of the expression (as in BOOST_PROTO_AUTO), the underlying object is copied once for *every* appearance in the expression. How do I make it such the underlying object doesn't copied many times? I want to have the copied expression also to have the property that the original expression had, i.e., everywhere an underlying object is referenced, they all refer to the same object. I will be grateful for any advice. #include <boost/proto/proto.hpp> #include <boost/proto/proto_typeof.hpp> #include <iostream> #include <sstream> #include <string> namespace proto=boost::proto; namespace mpl=boost::mpl; template<typename VT> struct Var { VT value; Var(const Var<VT> &that) { std::cout << "Copy\n"; value = that.value; } Var() { std::cout << "Default\n"; value = 0; } void assign(const VT v) { value = v; } }; typedef proto::literal<Var<int> > int32_; //typedef proto::terminal<Var<int> >::type int32_; int main() { int32_ a; std::cout << "Before\n"; BOOST_PROTO_AUTO(pr, (a)); std::cout << "After\n"; } Thanks, Manjunath

1 1

[mpl] defaults with associative sequence
by Manfred Doudar 06 Mar '10

06 Mar '10

Hi, Maybe I am misreading the documentation, but if I have an mpl::map and try and get an element associated with a key all's good, while if I assign a default - I get an error that mpl::at only takes 2 and not 3 template parameters. Simple example for sake of completness: using namespace boost::mpl; typedef map< pair<int, int_<0> > , pair<float, int_<1> > > m; at<m, float>::type::value; // Ok at<m, double, int_<2> >::type::value; // compiler error Indeed a look in boost/mpl/at.hpp even leads me to believe that mpl::at only takes two template parameters (maybe I mistaken), but documentation suggests otherwise. [Compiler: GCC-4.4.2 ; Boost-1.42] Am I doing something blatantly wrong? Cheers, -- Manfred

2 2

Problem with Boost Serialization
by Binh Luong 05 Mar '10

05 Mar '10

Hello, i have some problems with the serialization of boost. I am working now with a program and want to use boost to serialize an object to a xml archive. I have read the tutorials on the homepage and make the necessary steps but still get some errors while compiling: In file included from /home/v0d0i/libraries/boost_1_42_0/include/boost/archive/xml_oarchive.hpp:31, from message/remote/RemoteMessagingSystem.h:30, from message/remote/RemoteMessagingSystem.cpp:1: /home/v0d0i/libraries/boost_1_42_0/include/boost/archive/basic_xml_oarchive.hpp: In member function 'void boost::archive::basic_xml_oarchive<Archive>::save_override(T&, int) [with T = Message* const, Archive = boost::archive::xml_oarchive]': /home/v0d0i/libraries/boost_1_42_0/include/boost/archive/detail/interface_oarchive.hpp:64: instantiated from 'Archive& boost::archive::detail::interface_oarchive<Archive>::operator<<(T&) [with T = Message* const, Archive = boost::archive::xml_oarchive]' /home/v0d0i/libraries/boost_1_42_0/include/boost/archive/detail/interface_oarchive.hpp:72: instantiated from 'Archive& boost::archive::detail::interface_oarchive<Archive>::operator&(T&) [with T = Message*, Archive = boost::archive::xml_oarchive]' message/remote/RemoteMessagingSystem.cpp:147: instantiated from here /home/v0d0i/libraries/boost_1_42_0/include/boost/archive/basic_xml_oarchive.hpp:92: error: no matching function for call to 'assertion_failed(mpl_::failed************ boost::serialization::is_wrapper<Message* const>::************)' In file included from /home/v0d0i/libraries/boost_1_42_0/include/boost/archive/xml_iarchive.hpp:24, from message/remote/RemoteMessagingSystem.h:31, from message/remote/RemoteMessagingSystem.cpp:1: /home/v0d0i/libraries/boost_1_42_0/include/boost/archive/basic_xml_iarchive.hpp: In member function 'void boost::archive::basic_xml_iarchive<Archive>::load_override(T&, int) [with T = Message*, Archive = boost::archive::xml_iarchive]': /home/v0d0i/libraries/boost_1_42_0/include/boost/archive/xml_iarchive.hpp:80: instantiated from 'void boost::archive::xml_iarchive_impl<Archive>::load_override(T&, int) [with T = Message*, Archive = boost::archive::xml_iarchive]' /home/v0d0i/libraries/boost_1_42_0/include/boost/archive/detail/interface_iarchive.hpp:61: instantiated from 'Archive& boost::archive::detail::interface_iarchive<Archive>::operator>>(T&) [with T = Message*, Archive = boost::archive::xml_iarchive]' message/remote/RemoteMessagingSystem.cpp:164: instantiated from here /home/v0d0i/libraries/boost_1_42_0/include/boost/archive/basic_xml_iarchive.hpp:70: error: no matching function for call to 'assertion_failed(mpl_::failed************ boost::serialization::is_wrapper<Message*>::************)' make[2]: *** [RemoteMessagingSystem.o] Error 1 make[2]: Leaving directory `/home/v0d0i/workspace/trunk1/src/base' make[1]: *** [all-recursive] Error 1 make[1]: Leaving directory `/home/v0d0i/workspace/trunk1/src' make: *** [all-recursive] Error 1 It seems like there is something wrong with the Wrapper although i have defined the following Wrappers: BOOST_CLASS_IS_WRAPPER(Message*); BOOST_CLASS_IS_WRAPPER(Message* const); BOOST_CLASS_IS_WRAPPER(Message); I also used the boost::serialization::make_nvp for the name-value pairs purpose of xml archive. What am i doing wrong? Thanks, Ngoc Mai

2 10

[utility] swap
by Robert Jones 05 Mar '10

05 Mar '10

I'm sure I'm being a bit dense here, but apart from handling native arrays what does boost::swap give you that std::swap doesn't? Thanks, - Rob.

4 5

BGL using the VertexIndexMap with VertexList=listS
by khaled 05 Mar '10

05 Mar '10

Hello I'm using the BGL and wandering to use dijkstra_short_path I this code struct vertex1 { int step; int node; int MPI; int OMP; int acc; }; struct edge1 { double cost; }; typedef boost::adjacency_list< boost::listS, boost::listS, boost::directedS, vertex1, edge1> Graph; Graph g; std::vector<double> distances(num_vertices(g)); dijkstra_shortest_paths(g, from, weight_map(get(&edge1::cost, g)) .distance_map(make_iterator_property_map(distances.begin(), get(vertex_index, g)))); I have a problem with the VertexIndexMap (I guess is this the problem :) ) as I'm using a adjacenty_list with VertexList=listS does not have an internal vertex_index property. So, Please can you help me to fix this ? what is the VertexIndexMap to be used with the listS VertexList ?? Thanks -- K.H

2 1

Waiting for a thread on another thread
by Daniel Lidström 05 Mar '10

05 Mar '10

Hello! I have created a simple file logger using the active object pattern. This is intended to offload logging operations to a separate thread, to not disturb the main thread with time- consuming file operations. It works very nicely with boost::thread, but now I have a new desired functionality. The file logger keeps an internal queue of strings that need to be written to file. I want to know, from the main thread, when this queue is empty. To illustrate I have created a minimal, hopefully compilable, sample that shows what I am trying to achieve. #include <boost/thread/thread.hpp> #include <boost/thread/xtime.hpp> #include <boost/thread/condition.hpp> #include <boost/foreach.hpp> #include <boost/tr1/functional.hpp> #include <vector> #include <fstream> #include <string> class FileLogger { typedef boost::unique_lock<boost::mutex> unique_lock; std::ofstream logfile; bool running; boost::thread running_thread; boost::mutex mutex; boost::condition_variable condition; std::vector<std::string> queue; public: FileLogger(const std::string& filename) : logfile(filename.c_str()) , running(true) , running_thread(std::tr1::bind(&FileLogger::Run, this)) { } ~FileLogger() { running = false; condition.notify_one(); running_thread.join(); } void Log(const std::string& s) { unique_lock lock(mutex); queue.push_back(s); } void WaitForQueueFlush() { // ?? } private: void Run() { while( running ) { std::vector<std::string> copyList; { // wait 0.1 s here, for queue to fill up boost::xtime sleepTime; boost::xtime_get(&sleepTime, boost::TIME_UTC); sleepTime.nsec += 100*1000*1000; unique_lock lock(mutex); condition.timed_wait(lock, sleepTime); // fetch the current message list copyList.swap(queue); } BOOST_FOREACH(const std::string& s, copyList) { logfile << s << '\n'; } logfile.flush(); } } }; int main() { FileLogger fileLogger("logfile.txt"); fileLogger.Log(std::string(1000*1000, '*')); // this call should wait, synchronously, until // current queue has been flushed to disk fileLogger.WaitForQueueFlush(); } So the problem is to implement FileLogger::WaitForQueueFlush. How can I signal the main thread when the queue has been emptied? Thanks in advance! Regards, Daniel Lidström Stockholm, Sweden

2 1

[interprocess] Sharing data in a peer-to-peer fashion
by Brett Gmoser 05 Mar '10

05 Mar '10

Hello, I'm working on what seems to be a fairly interesting problem, and I'm looking for any interprocess experts to lend any advice. After reading all of the documentation for Interprocess, it seems that all of the examples work with a "one parent, many children" type model. The problem that I am having is that I am working with a "many children, no parent" model. My processes are spawned by the web server (and FastCGI), so there is no easy way to modify that code to manage the interprocess data. At least one instance of my program is meant to stay alive forever, so I'm not very concerned about deleting the interprocess data at any time. My problem however is the mutexes, and the stale locks that result if one of the processes crashes or exits abnormally. It seems that once an instance of my application crashes, no other instance may ever get a lock on the shared mutex, because the original process still holds a lock. I've thought of a few different ideas to solve this problem: * Using an interprocess shared_ptr for the mutex and data, with a custom deleter to remove all instances once the last application is exiting and the use count is zero. However this suffers from the same problem - it seems the use count is never decremented when the application exits abnormally (for example, kill -9, crash, or CTRL+C). * Using a "heart beat" type system to keep track of processes. My idea was to do something like this: Keep an interprocess associative array of process ID's mapped to last heartbeat time, with each process updating it's own heartbeat. At the same time, every other process (since there is no one parent process) must keep track of the heartbeats, and remove processes from the array which have not responded with a heartbeat in awhile. The problem is this - what about the mutex for the associative array? And the locks that another application might have on them? I wind up back at the point that I started at. The stale locks are destroyed if the mutex is deleted (via boost::interprocess::named_mutex::delete), and I can detect the stale lock pretty reliably with a timed try lock (wait 30 seconds or so to aquire the lock, if it can never be acquired then there is obviously a problem). But what of thread safety, since I now have to delete the lock and re-create it, where other processes might wind up doing the same thing? And what if those other processes are also trying to obtain a lock on the mutex at the same time I'm deleting and recreating it? Those are pretty much the only ideas I've had. Does anybody have anything better? Maybe some of you have tackled a similar problem? Thanks!

1 0

question about a asio example
by pedro chaparro 05 Mar '10

05 Mar '10

Hi, inthe example of a chat server usin asio library, http://www.boost.org/doc/libs/1_42_0/doc/html/boost_asio/example/chat/chat_… there is a fuction socket() , that socket_ value the function returns i use to each new connection with the server right? so if i have n users , i'll have n opened sockets?? i'll aprecciate to get me clear on this thanks tcp::socket& socket() { return socket_; } -- Ing Pedro Alonso Chaparro Valero Ciudad Politecnica de la Innovación iTEAM - Mobile Communications Group Polytechnic University of Valencia C\ Camino de Vera S/N, Edificio 8G 46022 Valencia, Spain

2 1

lambda::bind and abstract class - how to?
by Archie14 05 Mar '10

05 Mar '10

Here is the sample that fails to compile. Complain is about foo being abstract in IA. Any advise of how to make it work will be greatly appreciated. #include <boost/lambda/lambda.hpp> #include <boost/lambda/bind.hpp> #include <boost/ptr_container/ptr_vector.hpp> class IA { public: virtual int foo() const = 0; }; class B : public IA { public: B (int a) : _a(a) {}; int foo() const {return _a;} private: int _a; }; int _tmain(int argc, _TCHAR* argv[]) { boost::ptr_vector<IA> lst; lst.push_back(new B(1)); lst.push_back(new B(2)); boost::ptr_vector<IA>::iterator it = std::find_if (lst.begin(), lst.end(), boost::lambda::bind(&IA::foo, boost::lambda::_1) == 1); return 0; }

2 2

[CRC] Differences in crc_16_type and crc_32_type
by Ryan McConnehey 05 Mar '10

05 Mar '10

Work is wanting to use standard CRC algorithms for both 16 and 32 bit results. This would simplify documentation by not needing to use examples to define the process. The CRC library has predefined four common CRC algorithms. I've included three of the definitions for ease of discussion. Using Wikipedia and the truncated polynomial values, I identified the following algorithms. typedef crc_optimal<16, 0x8005, 0, 0, true, true> crc_16_type; typedef crc_optimal<16, 0x1021, 0xFFFF, 0, false, false> crc_ccitt_type; typedef crc_optimal<32, 0x04C11DB7, 0xFFFFFFFF, 0xFFFFFFFF, true, true> crc_32_type; crc_16_type = crc-16-IBM crc_ccitt_type = crc-16-ccitt crc_32_type = crc-32-ieee 802.3 Now for the questions. How do I know the CRC parameters for each algorithm? For example, if the reflection input for crc_ccitt_type was changed from false to true, is the algorithm result still crc-16-ccitt? Why are the parameters for crc_16_type and crc_32_type different? I expected only the truncated polynomial to change, not the initial remainder and final XOR value. Is it true that crc-32-ieee 802.3 is also called crc-32-ccitt? If that is correct why is the crc_16_type so different? Any clarification to my understanding would be helpful. Ryan

1 0

Boost ASIO issue
by A.Agrawal＠patrick.com.au 05 Mar '10

05 Mar '10

Hello All, Thanks for resolving my ASIO related issues so far, special thanks to Igor R. Now I am having a very strange problem. My program (based on chat server example in ASIO documentation) work fine on a simulator machine and have been tested thoroughly. But when I put it on another machine, it starts giving strange problems some seems to be random but I observed one of them very consistent. std::vector<boost::asio::const_buffer> buffers; buffers.push_back(boost::asio::buffer(_outbound_header)); buffers.push_back(boost::asio::buffer(_outbound_message)); buffers.push_back(boost::asio::buffer(_outbound_data)); boost::asio::async_write(*_socket, buffers, boost::bind(&DJClient::handle_write, this, boost::asio::placeholders::error)); For the above code, handle_write is never called. I can see on the server side that the server has received the request and has also sent the response. But I do not receive the response in the client side. It seems something is going wrong with io_service but don't know what. The same code has worked on a different machine. Any help will be highly appreciated. Regards, Anil Agrawal Patrick Technology & Systems Phone: +61 2 8333-6340

3 2

Boost.Thread and Boost.Function problems?
by anony 05 Mar '10

05 Mar '10

I have this situation: void my_thread(std::string const& a, std::string const& b) { } void spawner() { boost::thread(boost::function<void (std::string const&, std::string const&>(my_thread), "bla", "lala"); } This works, but is it possible that the string temporaries are destroyed before the thread starts running?

2 4

Problem with boost:thread
by Daniel Veneros 04 Mar '10

04 Mar '10

Hey, I'm trying to start a thread from a Class but the only way I did it was using a pointer. The thing is that when I assign the thread to the pointer it wont start unless I use join(). I need it to star right away is created just like when I create a thread (boost::thread myThread(funcName);) I was trying to use thread_group to do this, but create_thread is not working. *Here's an example of what I was doing:* *(Here I used the pointer)* class Thread { public: Thread(){}; virtual ~Thread(){}; virtual void run() = 0; void start(){m_Thread = new boost::thread( &Thread::run, this ); }; //wont start unless I add m_Thread.join(); private: boost::thread* m_Thread; }; *and now... I am trying to use thread_group:* class Thread { public: Thread(){}; virtual ~Thread(){}; virtual void run() = 0; void start(){g_Thread.create_thread(&Thread::run); }; private: boost::thread_group g_Thread; }; *But I receive an error:* /usr/local/include/boost/thread/detail/thread.hpp: In member function 'void boost::detail::thread_data<F>::run() [with F = void (Thread::*)()]': main.cpp:61: instantiated from here /usr/local/include/boost/thread/detail/thread.hpp:56: error: must use '.*' or '->*' to call pointer-to-member function in '((boost::detail::thread_data<void (Thread::*)()>*)this)->boost::detail::thread_data<void (Thread::*)()>::f (...)' make[2]: *** [build/Debug/GNU-MacOSX/main.o] Error 1 Im using netBeans on Mac OS X 10.6.2 Anyone knows how should I create this? or how to use simple boost::thread and launch it without using join()?? Thanks!!! Dann

4 8

[Boost.Multi-index] empty container allocates 1 unused node
by Jakub Jablonski 04 Mar '10

04 Mar '10

Hi, I was trying out some examples of using multi_index_container with custom allocator. I found out that even an empty container, on creation, allocates memory for a single node (but no element is stored inside). In other words, if I store N elements, the container allocates memory for N+1 elements. Is it a fault? If not, what is this memory used for? Is there any way to avoid this allocation? Regards, Jakub

2 1

Compiling Boost 1.42 in OS X
by Andrea Moglia 03 Mar '10

03 Mar '10

Hi, I tried many times to compile Boost 1.42 under OS X. However I always get relase mode. I inserted these commands: ./Bootstrap.sh --prefix=destination path ./bjam install I am looking for a way to compile Boost 1.42 in both debug and release mode. Please, could you tell me how to do that? Thank you. Andrea

3 2

Enumerating paths and euler paths in a graph
by Yaron Kretchmer 03 Mar '10

03 Mar '10

Hi There. I'm a boost newbie, so my apologies if this has been discussed before: I need to 1) Enumerate all paths of a certain length in a given graph. 2) Find all Euler paths in a given eulerian graph. Any idea on how to do that with boost? Thanks Yaron

1 0

boost::input_filter and negative char
by eial＠cs.bgu.ac.il 03 Mar '10

03 Mar '10

hello. I've seem to found a strange behavior within boost::input_filter, I'm writing data to a file using bzip2 compressor, in this issue all goes well, now when I read the data (I post process the data after the de/compression) because some of the chars are negative, then cases where there are two sequential -1 causes the filter to end processing even if the file isn't at eof. what can be done to prevent it? should this even happen? here are the test results: http://www.4shared.com/file/233035989/8bde1629/testresults.html

2 2

[traits/function_types/generic] Can F be called with {a0, ..., aN}?
by Rutger ter Borg 03 Mar '10

03 Mar '10

Hello, I have been trying to achieve assignment to a variant of functions, typedef boost::variant< boost::function< int >, boost::function< int, int > > variant_type; which is nice until you try to assign an ambiguous callable object to it, especially if the callable object has templates or similar. This has lead to my question: is there a way to know (without the "no matching function call" compiler error if {a0,...,aN} in F(a0,a1,...,aN) are permissible arguments to callable object/function F? I thought I had a nice solution by overriding boost::result_of< F(a0,a1..,aN)>::type in such way that it doesn't give compile errors if a type doesn't exist, but mpl::na (in conjunction with a has_result_of<T> meta-function). Then, writing functors like struct some_func { template< typename Sig > struct result { // no type defined here, so result_of<>::type is not defined } template< ... > struct result< enable_if arguments are acceptable > { typedef ... type; } R operator()( ... ) {} }; gives you the ability to answer the question for those particular functors. However, some widely used stuff like boost::bind always has a result_type, so this trick was a dead end. So, in short, does anyone know of a generic trick to know if F can be called with a set parameters {a0,...,aN} (without the compile error)? Thanks, Cheers, Rutger

2 6

[boost-users] [test] Boost.Test Mock
by Andrey Torba 03 Mar '10

03 Mar '10

Hi All, Whare can i find information about Boost.Test Mock? -- Regards, Andrey

2 4

[serialization] class versioning changes in boost 1.42
by David Raulo 02 Mar '10

02 Mar '10

Hi, It seems that the serialization library shipped with boost 1.42 changed the way class versions are handled. The version_type which used to be an unsigned int is now an uint_least16_t, although I found no mention of that in the release notes. The problem is that we are using a date-based versioning scheme for our classes (for example a developer making a change in some class on 2010-02-22 would increment the class version to 20100222). This scheme worked great for a couple of years, and helped us fix our backward compatibility bugs after the fact. Unfortunately, these big version numbers do not fit in 16-bit integers. As a consequence, the version string output in xml archives with the latest boost-serialization for this example would be 46206 instead of 20100222, breaking our reloading code. May I ask why this change was made? Would it be possible to revert it for the next boost release? If not, anyone has suggestions how we could fix our code while maintaining backward compatibility ? (we have old archives in the wild generated with various releases of our code, which we need to be able to reload). Thanks for any help, David.

7 33

[proto] defining function call operators on expressions
by Manjunath Kudlur 02 Mar '10

02 Mar '10

I am trying to define operator()(...) for my expressions. I want to be able to form expression of the form Program_(a,b) and call Program_(a, b)(10,20). Here, 'a' and 'b' are terminals and I have a mechanism shown in the code below that somehow gets the type suitable for the parameter position. Suppose 'a' is terminal<Var<int> >, I want the first parameter position in Program_(a,b) (pos1, pos2) to be of the type 'int'. typename boost::result_of<call_param_type<M>(const Expr &)>::type gives me that type for the Mth argument in the expression of the form Program_(a1,a2,...). Now, I am trying to use this to define operator()(...) in my program_expr class. That doesn't seem to work. However, if I define a separate function callfunc, that takes the expression and the arguments, that seems to work. In the following code, enabling the if 0'ed out code results in compilation errors. How do I go about defining operator()(...) in my program_expr class with the above property? Thanks, Manjunath #include <boost/proto/proto.hpp> #include <boost/proto/proto_typeof.hpp> #include <boost/mpl/bool.hpp> #include <boost/mpl/assert.hpp> #include <iostream> #include <sstream> #include <string> namespace proto=boost::proto; namespace mpl=boost::mpl; unsigned int ids; template<typename VT> struct Var { unsigned int id; Var() { id = ++ids; } }; typedef proto::terminal<Var<int> >::type int32_; typedef proto::terminal<Var<float> >::type float_; struct program_ {}; template<class E> struct program_expr; struct program_domain : proto::domain<proto::pod_generator<program_expr> > { }; struct _var_type : proto::callable { template<typename Sig> struct result; template<typename This, typename T> struct result<This(const Var<T> &)> { typedef T type; }; }; struct var_type : proto::or_< proto::when<proto::terminal<Var<proto::_> >, _var_type(proto::_value)> > {}; template<int N> struct call_param_type : proto::or_< proto::when< proto::function< proto::terminal<program_>, proto::vararg<proto::terminal<Var<proto::_> > > >, var_type(proto::_child_c<N+1>)> > {}; template <typename Expr> struct program_expr { BOOST_PROTO_BASIC_EXTENDS(Expr, program_expr<Expr>, program_domain); BOOST_PROTO_EXTENDS_SUBSCRIPT(); typedef void result_type; #if 0 result_type operator()(typename boost::result_of<call_param_type<0>(const Expr &)>::type x) { std::cout << "program with one arg\n"; } result_type operator()(typename boost::result_of<call_param_type<0>(const Expr &)>::type x, typename boost::result_of<call_param_type<1>(const Expr &)>::type y) { std::cout << "program with two args\n"; } #endif }; template<typename Expr> void callfunc(const Expr &e, typename boost::result_of<call_param_type<0>(const Expr &)>::type x) { std::cout << "program with one arg\n"; } template<typename Expr> void callfunc(const Expr &e, typename boost::result_of<call_param_type<0>(const Expr &)>::type x, typename boost::result_of<call_param_type<1>(const Expr &)>::type y) { std::cout << "program with two args\n"; } template<typename A0> typename proto::result_of::make_expr<proto::tag::function , program_domain , program_ , A0 const &>::type const Program_(A0 const &a0) { return proto::make_expr<proto::tag::function, program_domain>( program_(), boost::ref(a0)); } template<typename A0, typename A1> typename proto::result_of::make_expr<proto::tag::function , program_domain , program_ , A0 const & , A1 const &>::type const Program_(A0 const &a0, A1 const &a1) { return proto::make_expr<proto::tag::function, program_domain>( program_(), boost::ref(a0), boost::ref(a1)); } int main() { int32_ a,b,c; callfunc(Program_(a, b), 10, 20); #if 0 Program_(a, b)(10, 20); #endif }

3 8

problem with memcpy to shared memory
by Cuneyt Taskiran 02 Mar '10

02 Mar '10

Hi, I want to create a buffer in shared memory and have modified the example code provided in Boost.Interprocess to get the following class: template<typename ItemType> class SharedMemoryBufferMock { private: ItemType* m_data; // array of ItemType items ItemType* m_read_ptr; // points to next buffer location to be read from ItemType* m_write_ptr; // points to next buffer location to be written to std::string m_segmentName; // unique name for the memory segment that holds the buffer object std::string m_objectName; // unique name for the buffer object unsigned long m_nItems; unsigned long m_capacity; public: SharedMemoryBufferMock( unsigned long maxItemCount ); virtual ~SharedMemoryBufferMock(); unsigned long capacity() { return m_capacity; } unsigned long size() { return m_nItems; } bool isFull() { return m_nItems == m_capacity; } bool isEmpty() { return m_nItems == 0; } ItemType* read(); void write( ItemType* item_ptr); }; /* * Implementation of the templated methods. */ template<typename ItemType>SharedMemoryBufferMock<ItemType>::SharedMemoryBufferMock( unsigned long maxItemCount ) { if( maxItemCount == 0 ) { std::cerr << "Buffer cannot be created with a capacity of zero!" << std::endl; exit(1); } // Create unique name for memory segment using PID of current process. std::stringstream pid_str; pid_str << "BufferMemorySegment_" << getpid(); m_segmentName = pid_str.str(); pid_str.str(""); pid_str << "BufferMemoryObject_" << getpid(); m_objectName = pid_str.str(); boost::interprocess::shared_memory_object::remove(m_segmentName.c_str()); m_capacity = maxItemCount; // Create a new segment with given name and size boost::interprocess::managed_shared_memory segment( boost::interprocess::create_only, m_segmentName.c_str(), //memSize 65536 ); // Create the buffer data object with specified item capacity. m_data = segment.construct<ItemType> ( m_objectName.c_str() ) // name of the object [maxItemCount] // number of items (ItemType()); // ctor for elements // Initialize read and write locations. m_write_ptr = m_read_ptr = m_data; } template<typename ItemType> void SharedMemoryBufferMock<ItemType>::write( ItemType* item_ptr ) { if( isFull() ) { std::cerr << "Cannot write to buffer, it's full. Read one or more elements first!" << std::endl; exit(1); } std::memcpy( m_write_ptr, item_ptr, sizeof(ItemType) ); m_write_ptr++; m_nItems++; } When I test the code using the following: SharedMemoryBufferMock<int> sharedBuf(100); for( int i = 0; i < 10; i++ ) { cout << "writing " << i << endl; sharedBuf.write( &i ); } I get a segmentation fault at the memcpy step. I've been at this for a couple of hours now and cannot see what I'm doing wrong. Any comments would be greatly appreciated. Thanks, C

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boost/accumulators - chi-square test, calculation of p-values
by Christine SINOQUET 02 Mar '10

02 Mar '10

Hello everybody, I have to implement the Pearson chi-square test in C++. I do not succeed in finding the appropriate instructions to use boost for this purpose. I am not even sure of the library file I ought to use. Many thanks in advance for any help. Best regards, Christine Sinoquet // convention: // df: degrees of freedom // css_observed: observed chi-squared score #include <boost/accumulators/statistics/stats.hpp> void chi_squared_test(){ typedef accumulator_set<double, stats<tag::p_square_cumulative_distribution> > accumulator_t; accumulator_t acc(tag::p_square_cumulative_distribution::<???tag in connexion with df (degrees of freedom)???>); double p = acc(<access to cumulative function for css_observed>) ... } _________________________________________________________________________________ Note 1: As far as I can see, the code below found on Internet does not correspond at all to my boost library : // df: degrees of freedom // css_observed: observed chi-squared score boost::math::chi_squared mydist(df); // usage of the cdf accessor function (cumulative distribution function) to compute the p-value // corresponding to the observed chi-squared score with df degrees of freedom. // p(css <= css_observed) = F(css_observed) float p = boost::math::cdf(mydist,css_observed); // p-value = 1 - p is the probability of observing a chi-squared score at least as extreme as css_observed, // if one assumes the null hypothesis holds. ___________________________________________________________________________________ Note 2: Below is the content of .../boost/include/boost/accumulators/statistics : count.hpp covariance.hpp density.hpp directory error_of.hpp error_of_mean.hpp extended_p_square.hpp extended_p_square_quantile.hpp kurtosis.hpp max.hpp mean.hpp median.hpp min.hpp moment.hpp parameters peaks_over_threshold.hpp pot_quantile.hpp pot_tail_mean.hpp p_square_cumulative_distribution.hpp p_square_quantile.hpp skewness.hpp stats.hpp sum.hpp tail.hpp tail_mean.hpp tail_quantile.hpp tail_variate.hpp tail_variate_means.hpp times2_iterator.hpp variance.hpp variates weighted_covariance.hpp weighted_density.hpp weighted_extended_p_square.hpp weighted_kurtosis.hpp weighted_mean.hpp weighted_median.hpp weighted_moment.hpp weighted_peaks_over_threshold.hpp weighted_p_square_cumulative_distribution.hpp weighted_p_square_quantile.hpp weighted_skewness.hpp weighted_sum.hpp weighted_tail_mean.hpp weighted_tail_quantile.hpp weighted_tail_variate_means.hpp weighted_variance.hpp with_error.hpp

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Re: [Boost-users] [Fusion] transform / transform_view / binary sequence iteration
by Hicham Mouline 02 Mar '10

02 Mar '10

-----Original Message----- From: "Thomas Taylor" [thomas.taylor(a)univie.ac.at] Date: 02/03/2010 11:49 AM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] [Fusion] transform / transform_view / binary sequence iteration Hi! Started out with tuple but soon moved to fusion as it suits my needs much better, so thanks for fusion! My problem is the following: list<A,B,C> seq2(1,2,3); list<W<A>,W,W<C> > seq1; struct fa { typedef unsigned int result_type; template <typename S1, typename S2> result_type operator()(const S1& s1, const S2& s2) const { return s1(s2); // this calls W<A>(A), W(B), W<C>(C) } }; struct fb { typedef std::vector<unsigned int> result_type; template <typename T> result_type operator()(const result_type& a, const T& t) const { result_type a2(a); a2.push_back(t); return a2; } }; accumulate( transform(seq1,seq2,fa()),fb() ); /* The above yields an error: no matching function for call to ‘accumulate(boost::fusion::transform_view<const boost::fusion::list<W<double>, W<double>, W<double>, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_>, const boost::fusion::list<double, double, double, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_>, database::histogram::fb>) */ How can I use a transform_view (the result of transform(S1,S2,F)) as input for accumulate? Thank you, Thomas _______________________________________________ In my basic experience, this has been a matter of constness. Checkout fusion docs and make sure you follow exactly the function signatures. Oh! you need an initial state for accumulate() rds,

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[Fusion] transform / transform_view / binary sequence iteration
by Thomas Taylor 02 Mar '10

02 Mar '10

Hi! Started out with tuple but soon moved to fusion as it suits my needs much better, so thanks for fusion! My problem is the following: list<A,B,C> seq2(1,2,3); list<W<A>,W,W<C> > seq1; struct fa { typedef unsigned int result_type; template <typename S1, typename S2> result_type operator()(const S1& s1, const S2& s2) const { return s1(s2); // this calls W<A>(A), W(B), W<C>(C) } }; struct fb { typedef std::vector<unsigned int> result_type; template <typename T> result_type operator()(const result_type& a, const T& t) const { result_type a2(a); a2.push_back(t); return a2; } }; accumulate( transform(seq1,seq2,fa()),fb() ); /* The above yields an error: no matching function for call to ‘accumulate(boost::fusion::transform_view<const boost::fusion::list<W<double>, W<double>, W<double>, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_>, const boost::fusion::list<double, double, double, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_, boost::fusion::void_>, database::histogram::fb>) */ How can I use a transform_view (the result of transform(S1,S2,F)) as input for accumulate? Thank you, Thomas

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on_error and calc4.cpp
by Xavier Pegenaute 02 Mar '10

02 Mar '10

Hi, I have some question about on_error behavior. - Why the error explanation is only shown when the user changes a number by a some other characters?, may be because there is not rule for "+-/*" ? is it necessary to be a rule to show where the error is? - When is useful to write more than one on_error?, may be when you want to show different messages for each different rule? - What is the rule to use as on_error first parameter?, I guess the most general rule of the parsing zone. Thanks & Regards. Xavi.

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[Proto] Processing literal strings in context
by Steffen Rauh 02 Mar '10

02 Mar '10

Hi all, I am using Boost.Proto with Boost 1.42.0 and Visual Studio 2005/2008. I try to handle literal strings in the context of my DSEL: struct CContext { ... template<> struct eval<CExpression<proto::terminal<const char*>::type> > { typedef void result_type; result_type operator()(CExpression<proto::terminal<const char*>::type> Expr, CContext& Ctx) const { return; } }; ... }; But the eval for literal strings is never matched. Instead the general proto::tag::terminal eval is matched which is defined afterwards. I tried several variations like char const[proto::N] and the like, without success. What am I missing here? A full example follows at the end. Regards, Steffen ------------------------------ #include <iostream> #include <boost/proto/proto.hpp> namespace proto = boost::proto; struct CTerminal; struct CGrammar : proto::or_< proto::shift_right<CGrammar, CGrammar>, proto::terminal<proto::_> > { }; struct CDomain; template <typename TExpr> struct CExpression : proto::extends<TExpr, CExpression<TExpr>, CDomain> { typedef proto::extends<TExpr, CExpression<TExpr>, CDomain> base_type; CExpression(const TExpr& Expr = TExpr()) : base_type(Expr) { } }; struct CDomain : proto::domain<proto::generator<CExpression>, CGrammar> { }; struct CTerminal : CExpression<proto::terminal<int>::type> { typedef proto::terminal<int>::type expr_type; CTerminal() : CExpression<expr_type>(expr_type::make(int(0))) { } template <typename TExpr> void operator=(TExpr& Expr) { CContext Ctx; proto::eval(Expr, Ctx); return; } }; // typedef CExpression<proto::terminal<char const[8]>::type> TLiteralString; // typedef CExpression<proto::terminal<char const[proto::N]>::type> TLiteralString; typedef CExpression<proto::terminal<const char*>::type> TLiteralString; struct CContext { template<typename TExpr, typename Tag = typename TExpr::proto_tag> struct eval { }; template<> struct eval<CTerminal> { typedef void result_type; result_type operator()(const CTerminal& Expr, CContext& Ctx) const { std::cout << "CTerminal\n"; return; } }; // why is the literal string not matched by this eval??? template<> struct eval<TLiteralString> { typedef void result_type; result_type operator()(TLiteralString Expr, CContext& Ctx) const { std::cout << "Literal string \"" << proto::value(Expr) << "\"\n"; return; } }; // instead the literal string matches this template<typename TExpr> struct eval<TExpr, proto::tag::terminal> { typedef void result_type; result_type operator()(const TExpr& Expr, CContext& Ctx) const { std::cout << "*** Terminal \"" << proto::value(Expr) << "\"\n"; std::cout << "*** " << typeid(Expr).name() << "\n"; std::cout << "*** " << typeid(TLiteralString).name() << "\n"; return; } }; template<typename TExpr> struct eval<TExpr, proto::tag::shift_right> { typedef void result_type; result_type operator()(const TExpr& Expr, CContext& Ctx) const { std::cout << "ShiftRight\n"; proto::eval(proto::left(Expr), Ctx); proto::eval(proto::right(Expr), Ctx); return; } }; }; int main(int argc, char* argv[]) { CTerminal Foo, Bar; Foo = Bar >> "keyword"; return 0; } -- Sicherer, schneller und einfacher. Die aktuellen Internet-Browser - jetzt kostenlos herunterladen! http://portal.gmx.net/de/go/atbrowser

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[android] Boost + Android NDK
by Agustín K-ballo Bergé 02 Mar '10

02 Mar '10

I would like to hear from other's experiences on using Boost togheter with Android NDK. Personally, while I have been unable to build Boost, I am successfuly using (pieces of): · Array · Assign · Date Time · Enable If · Flyweight · Function Types · Fusion · GIL · Integer · MPL · Preprocessor · Random · Rational · Spirit (which itself uses Proto) · Tuple · Type Traits as well as the proposed: · Endian · LA (Static Size Linear Algebra) · MSM I was forced to hack code here and there, due to lack of exceptions and RTTI. I also had to add configuration macros for endiannes, and a DateTime related macro to have microsec_clock available. Anyone else would like to share its experience? Particularly, was anyone succesful to build boost on Android? And finally, is there interest in patching Boost to make it more 'Android friendly'? This would also benefit other (possibly embedded) systems which run with exceptions and RTTI turned off. Agustín K-ballo Bergé.-

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Re: [Boost-users] multinomial tree-like container
by Hicham Mouline 02 Mar '10

02 Mar '10

-----Original Message----- >From: "Paul Dugas" [paul(a)dugas.cc] >Date: 02/03/2010 06:06 AM >To: "boost-users" <boost-users(a)lists.boost.org> >Subject: Re: [Boost-users] multinomial tree-like container On Mon, Mar 1, 2010 at 5:53 AM, Hicham Mouline <hicham(a)mouline.org> wrote: >> Is there a library that provides a public container that has the structure of a tree where there are top nodes, and each node can have 0 to N children? >Is "Property Tree" what you're looking for? >http://www.boost.org/doc/libs/1_42_0/doc/html/property_tree.html >PD That one looks geared towards reading/writing config. I have no IO to do, just a data structure that resembles a n-ary tree where I may want to apply an algorithm on all the nodes. As far as I could find: 1. Boost.Tree from summer of code 2006 in boost vault, though it seems to have implemented only binary trees 2. ntree.hh from http://tree.phi-sci.com/ seems to be what I want. 3. Boost Graph library is a superset of what I need. Regards,

1 0

Boost Bind
by Etienne Pretorius 02 Mar '10

02 Mar '10

Hello List, I am trying to use boost::signals with boost bind... but I always get this compiler error: 1>c:\program files\boost\boost_1_42\boost\bind\bind.hpp(69) : error C2825: 'F': must be a class or namespace when followed by '::' 1> c:\program files\boost\boost_1_42\boost\bind\bind_template.hpp(15) : see reference to class template instantiation 'boost::_bi::result_traits<R,F>' being compiled 1> with 1> [ 1> R=boost::_bi::unspecified, 1> F=__w64 long (__stdcall ticketman::Window::* )(UINT,WPARAM,LPARAM) 1> ] I am unable to make sence of it... /*CODE*/ /* boost::signal masqurading as a Window Procedure */ static boost::signal<::LRESULT (::HWND,::UINT,::WPARAM,::LPARAM)> WindowProc; /* Window Procedure */ ::LRESULT CALLBACK WndProc( ::HWND hWnd, ::UINT message, ::WPARAM wParam, ::LPARAM lParam ) { return WindowProc(hWnd, message, wParam, lParam); }; class Window : public boost::noncopyable { public: /* Deconstructor */ ~Window( ) { WindowProc.disconnect(m_Connection); }; private: friend ::LRESULT CALLBACK WndProc(::HWND, ::UINT, ::WPARAM, ::LPARAM); virtual ::LRESULT CALLBACK WndProc(::UINT, ::WPARAM, ::LPARAM) = 0; protected: /* Constructor */ Window( ::HINSTANCE hInstance ) : m_Window(NULL) { m_Connection = WindowProc.connect( boost::bind( &Window::WndProc, this, _1, _2, _3 ) ); m_Instance = hInstance;//Might need some work... }; /* Varibles */ static ::HINSTANCE m_Instance; ::HWND m_Window; boost::signals::connection m_Connection; }; I have tried enabling WIN_API for boost and also trying to turn the pure virtual method into a method... still no luck. Thank you, Etienne

2 3

multinomial tree-like container
by Hicham Mouline 02 Mar '10

02 Mar '10

Hello, Is there a library that provides a public container that has the structure of a tree where there are top nodes, and each node can have 0 to N children? regards,

2 1

Creating a map between two sets of classes
by Gokulakannan Somasundaram 02 Mar '10

02 Mar '10

Hi, I have a requirement where in i have a set of classes and they have a one on one correspondence with another set of classes. Consider something like this a) template<class A> class Walkers { int walk( Context<A>* context ); }; The set of Context classes are not templates. They are individual classes. I need to create a mapping between these two sets. One way, i could think of is to create a typelist and refer to the class at the appropriate location. But i feel that is more error prone, as i may mismatch the Contexts in the typelist. Can someone advise me how to do this using any of the boost libraries? Thanks, Gokul.

2 5

Bug: boost 1.42 doesn't download a .lib
by Trevin Murakami 02 Mar '10

02 Mar '10

I finally had to grab this manually from SourceForge. For some reason the installer won't grab libboost_unit_test_framework-vc90-mt-s-1_42.lib, and I needed it. This was while setting it to download everything for VC90 and manually trying to set it to download all files for the Boost Unit Test Framework. -Trevin "2 hours of downloading through a tool, 15 minutes SourceForge search" Murakami

1 0

Using the Boost Preprocessor
by Rowan Sylvester-Bradley 02 Mar '10

02 Mar '10

I've got an application where I need to generate a lot of repetitive sections of 8051 assembler code. For this I need a pre-processor or macro processor that has facilities for iteration and/or recursion. I'm currently using a stand-alone C preprocessor (MCPP) to do conditional assembly etc., and someone suggested that the Boost pre-processor library might give me the facilities I need for these repetitive code sections. What do I have to download to get just the preprocessor libraries? Also, can I use these libraries with any C or C++ preprocessor (such as MCPP), or do I need something specific? I guess this boils down to - does the Boost librbary use any compiler/preprocessor featires that I wouldn't find in a standard C preprocessor? Thanks for your help. These questions arise because I'm not using C or C++, so the rest of Boost is presumably of no use to me - I just need the preprocessor bit. I'm using Windows Vista, so any tools need to be Windows compatible... Thanks - Rowan

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Boost.Test 1.42 --report_sink="path with spaces"
by Chris Hoeppler 01 Mar '10

01 Mar '10

Hi, when calling some my_unit_test module with my_unit_test --report_level=detailed --report_sink="foo bar" then the report isn't written to a file "foo bar" but to a file "foo". Is there any way to pass a path containing spaces to the report_sink option? Regards Chris

2 1

Boost.Log formal review upcoming
by Vladimir Prus 01 Mar '10

01 Mar '10

Boosters, the formal review of the Boost.Log library, written by Andrey Semashev, will start in a week from now, on March 8, 2010 and will run through March 17, 2010. The documentation for the current version is available at: http://boost-log.sourceforge.net The downloads at at: http://sourceforge.net/projects/boost-log Because the library is relatively big and important, you might want to take a look in advance, without waiting for the formal review. Please note that reports of real-world usage will be particularly appreciated -- even if you don't have the time to to do everything formal review checklist requires please still report your experiences. To clarify timelines, the formal reviews are accepted from 23:59, March 7, PST = 2:59, March 8, EST = 7:59 March 8, GMT = 10:59, March 8 MSK until 23:59, March 17, PST = 2:59, March 18, EST = 7:59 March 18, GMT = 10:59, March 18 MSK Reviews submitted outside of this frame are not guaranteed to be processed. Thanks, Volodya

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[GIL] Status of Ticket #2831?
by Olivier Tournaire 01 Mar '10

01 Mar '10

Hi, A colleague of mine opened a ticket more than a year ago ( https://svn.boost.org/trac/boost/ticket/2831) for a GIL defect. In fact, the custom color converter for color_converted_view on any_view is not plugged. The problem is also described in the title of the ticket. What is the status of this ticket? The changes are very simple, and are still not done in 1.42 version. Instead of: template <typename DstP, typename Result> struct color_converted_view_fn { typedef Result result_type; template <typename View> result_type operator()(const View& src) const { return result_type(color_converted_view<DstP>(src)); } }; There should be: template <typename DstP, typename Result, typename CC = default_color_converter> struct color_converted_view_fn { typedef Result result_type; color_converted_view_fn(CC cc = CC()): _cc(cc) {} template <typename View> result_type operator()(const View& src) const { return result_type(color_converted_view<DstP>(src, _cc)); } private: CC _cc; }; Best regards. Olivier

2 3

[regex] wildcard matching byte not character
by Richard Clokie 01 Mar '10

01 Mar '10

Hi all I'm having trouble with the behaviour of the wildcard character when using boost regex and unicode strings. I would expect a . to match a character, not a byte, but that's not the behaviour I'm seeing. I would have thought one wildcard would match any previous character, but for multi-byte characters in UTF-8 I have to use multiple wildcards to match them. I would appreciate it if someone could explain whether this is expected behaviour or not, or if there are flags that control this. What I'm trying to accomplish is to match a pattern (in UTF-8 ) against a string (in UTF-8). I'm creating icu UnicodeStrings since I'm having other problems with straight UTF-8 char*s and my platform doesn't support w_chars. I can show examples of the non-UnicodeString problems if desired. I'm using 1.42 Test program follows - output is: $ g++ regex2.cc -l icui18n -l icuuc -l icudata -lboost_regex -o example && ./example unicodeString tests failed Success! ---- #include <iostream> #include <boost/regex.hpp> #include <boost/regex/icu.hpp> using namespace boost; using namespace std; int main(){ static const char input[]={0xC2,0xA3, 0xC3,0x98, 0xC2,0xB2, 0 }; UnicodeString uInput(input); const char match1[] = {0xC2,0xA3,0x2E,0xC2,0xB2, 0} ; // one . const char match2[] = {0xC2,0xA3,0x2E,0x2E,0xC2,0xB2, 0} ; // two .s UnicodeString uMatch1(match1); UnicodeString uMatch2(match2); u16match what; cout << "unicodeString tests" << endl; if(u32regex_search( uInput , what, // one . fails make_u32regex(uMatch1,regex::extended))) { cout << "Success!" << endl; } else { cout << "failed" << endl; } if(u32regex_search( uInput , what, // two . succeeds make_u32regex(uMatch2,regex::extended))) { cout << "Success!" << endl; } else { cout << "failed" << endl; } }

2 2

[GIL new_io] Some questions about TIFF handling
by Olivier Tournaire 01 Mar '10

01 Mar '10

Hi all (and in particular Christian), I have some questions about TIFF reader/writer in GIL new_io. First, I do not understand why *bits32f* are scoped in the range [0.f ... 1.f]. It is for our applications a real limitation because we use float TIFF images not scoped in the range. We thus have to define a new type (e.g. bits32F) which is not scoped and simply typedef float bits32F. In addition, why double is not "typedefed" by default? We also have to define a new type: typedef double bits64f. Double however seems to be supported in the writer. Last, but not least, there is no support for *tiled TIFF*. Nothing about tiled TIFF is defined in tiff_tags.hpp. Maybe we could add in tiff_device_base a read_tile method, similar to read_scaline (sic), but which simply swap TIFFReadScanline with TIFFReadTile. So, do you plan to add this stuffs in the new version of GIL io? Maybe I could help. Let me know. Best regards, Olivier

3 2

BGL: A* search & implicit graph
by Damien Maupu 01 Mar '10

01 Mar '10

Hi, Some weeks ago, I wrote on this mailing list, that I succeed achieving an A* search using an implicit graph. A Boost user emailed me to send him an example of my implementation. As the web is lacking of such example, I think the best place to send such example would be here as it might help others in the future. My example might not be the best, the most optimized or most well-coded. I am open to suggestions, corrections and comments. Let me know if something unclear. The code comes below. Few words to quickly explain the code: The goal is to A* search a graph (named m_SearchGraph) that grows (i.e. m_SearchGraph is implicit) based on another graph (named MyGraph). The search starts from 2D point (_startX, _startZ) and must get enough close (less than error "_epsilon") to 2D point (_goalX, _goalZ). The example is dumb and simply increment current position whatever the node in MyGraph (i.e. currX++, currZ++, currWeight += sqrt(2)). User need to adapt this dummy behavior depending on its needs (search for "//to change"). Most adaptations have to be done in "examine_vertex" (and also by providing ref/ptr to needed objects to the visitor constructor) PS: The implementation assumes both graphs are adjacency_list with "vecs" for both edges and vertices (in which a vertex/edge descriptor is equivalent to an "int", for my understanding) PS2: Id == descriptor (e.g. edgeId == edge_descriptor) ==================================================================================== ==================================================================================== astarSearch.h ==================================================================================== #ifndef ASTARSEARCH_H #define ASTARSEARCH_H #include <boost/graph/astar_search.hpp> #include "myGraph.h" class AStarSearch { public: AStarSearch(MyGraph * _myGraph); virtual ~AStarSearch(); bool findPath(MyGraph::VertexId _startMyGraphVertextId, double _startX, double _startZ, double _goalX, double _goalZ, double _epsilon); private: //search graph struct m_Vertex { m_Vertex() { currX = 0.0; currZ = 0.0; refMyGraphVertexId = -1; prevVertexId = -1; double inf = numeric_limits<double>::max BOOST_PREVENT_MACRO_SUBSTITUTION (); distance = inf; cost = inf; color = white_color; } //properties for heuristic / visitor double currX; double currZ; int refMyGraphVertexId; //reference to correspondant vertex in myGraph //properties required by astar_search_no_init(...) int prevVertexId; // == predecessor double distance; double cost; default_color_type color; }; struct m_Edge { m_Edge() { weight = 0.0; } double weight; }; //graph property = save the vertex id when goal is reached //saving goal vertex could be also saved by a reference to an int passed to the visitor class typedef property<graph_name_t, int> m_GraphProperty; typedef adjacency_list<vecS, vecS, directedS, m_Vertex, m_Edge, m_GraphProperty> m_SearchGraph; typedef graph_traits<m_SearchGraph>::vertex_descriptor m_VertexId; typedef graph_traits<m_SearchGraph>::edge_descriptor m_EdgeId; typedef graph_traits<m_SearchGraph>::vertex_iterator m_VertexIt; typedef graph_traits<m_SearchGraph>::adjacency_iterator m_AdjacencyIt; typedef graph_traits<m_SearchGraph>::edge_iterator m_EdgeIt; typedef graph_traits<m_SearchGraph>::out_edge_iterator m_OutEdgeIt; //heuristic class m_Heuristic : public astar_heuristic<m_SearchGraph, double> { public: m_Heuristic(m_SearchGraph & _searchGraph, double _goalX, double _goalZ); virtual ~m_Heuristic(); double operator()(m_VertexId _currVertexId); private: m_SearchGraph & m_searchGraph; double m_goalX; double m_goalZ; }; //exception to end search struct m_endSearch{}; //visitor class m_Visitor : public default_astar_visitor { public: m_Visitor(MyGraph * _myGraph, m_SearchGraph & _searchGraph, double _goalX, double _goalZ, double _epsilon); virtual ~m_Visitor(); void examine_vertex(m_VertexId _currVertexId, const m_SearchGraph & _graph); private: MyGraph * m_myGraph; m_SearchGraph & m_searchGraph; double m_goalX; double m_goalZ; double m_epsilon; }; void m_printSearchGraph(m_SearchGraph & _searchGraph); list<int> m_getPath(m_SearchGraph & _searchGraph, m_VertexId _vertexId); vector< list<int> > m_getAllPaths(m_SearchGraph & _searchGraph); void m_printPath(list<int> _path); void m_printShortestPath(m_SearchGraph & _searchGraph); void m_printAllPaths(m_SearchGraph & _searchGraph); MyGraph * m_myGraph; }; #endif ==================================================================================== ==================================================================================== ==================================================================================== aStarSearch.cpp ==================================================================================== ==================================================================================== #include "aStarSearch.h" AStarSearch::AStarSearch(MyGraph * _myGraph): m_myGraph(_myGraph) { } AStarSearch::~AStarSearch() { } bool AStarSearch::findPath(MyGraph::VertexId _startMyGraphVertextId, double _startX, double _startZ, double _goalX, double _goalZ, double _epsilon) { m_SearchGraph searchGraph; m_Heuristic heuristic(searchGraph, _goalX, _goalZ); m_Visitor visitor(m_myGraph, searchGraph, _goalX, _goalZ, _epsilon); //typedef property maps typedef property_map<m_SearchGraph, vertex_index_t>::type IndexMap; typedef property_map<m_SearchGraph, double m_Edge::*>::type WeightMap; typedef property_map<m_SearchGraph, int m_Vertex::*>::type PredecessorMap; typedef property_map<m_SearchGraph, double m_Vertex::*>::type DistanceMap; typedef property_map<m_SearchGraph, double m_Vertex::*>::type CostMap; typedef property_map<m_SearchGraph, default_color_type m_Vertex::*>::type ColorMap; //create property maps IndexMap indexMap = get(vertex_index, searchGraph); WeightMap weightMap = get(&m_Edge::weight, searchGraph); PredecessorMap predecessorMap = get(&m_Vertex::prevVertexId, searchGraph); DistanceMap distanceMap = get(&m_Vertex::distance, searchGraph); CostMap costMap = get(&m_Vertex::cost, searchGraph); ColorMap colorMap = get(&m_Vertex::color, searchGraph); double inf = numeric_limits<double>::max BOOST_PREVENT_MACRO_SUBSTITUTION (); double zero = double(); //add & init first vertex m_VertexId startVertexId = add_vertex(searchGraph); m_Vertex & startVertex = searchGraph[startVertexId]; startVertex.currX = _startX; startVertex.currZ = _startZ; startVertex.refMyGraphVertexId = _startMyGraphVertextId; startVertex.prevVertexId = startVertexId; startVertex.distance = zero; startVertex.cost = heuristic(startVertexId); try { astar_search_no_init(searchGraph, startVertexId, heuristic, visitor, predecessorMap, costMap, distanceMap, weightMap, colorMap, indexMap, std::less<double>(), std::plus<double>(), inf, zero); } catch(m_endSearch end) { m_printSearchGraph(searchGraph); m_printShortestPath(searchGraph); m_printAllPaths(searchGraph); return true; } return false; } AStarSearch::m_Heuristic::m_Heuristic(m_SearchGraph & _searchGraph, double _goalX, double _goalZ): m_searchGraph(_searchGraph), m_goalX(_goalX), m_goalZ(_goalZ) { } AStarSearch::m_Heuristic::~m_Heuristic() { } double AStarSearch::m_Heuristic::operator()(m_VertexId _currVertexId) { m_Vertex currVertex = m_searchGraph[_currVertexId]; return sqrt(pow(m_goalX - currVertex.currX, 2) + pow(m_goalZ - currVertex.currZ, 2)); //for A* search //return 0; //for BFS search } AStarSearch::m_Visitor::m_Visitor(MyGraph * _myGraph, m_SearchGraph & _searchGraph, double _goalX, double _goalZ, double _epsilon): m_myGraph(_myGraph), m_searchGraph(_searchGraph), m_goalX(_goalX), m_goalZ(_goalZ), m_epsilon(_epsilon) { } AStarSearch::m_Visitor::~m_Visitor() { } void AStarSearch::m_Visitor::examine_vertex(m_VertexId _currVertexId, const m_SearchGraph & _graph) { //get currVertex / currX / currZ m_Vertex currVertex = m_searchGraph[_currVertexId]; double currX = currVertex.currX; double currZ = currVertex.currZ; //check if goal is reached if(sqrt(pow(m_goalX - currX, 2) + pow(m_goalZ - currZ, 2)) < m_epsilon) { set_property(m_searchGraph, graph_name, _currVertexId); //_currVertexId == goal vertex id throw m_endSearch(); } //declare currMyGraphVertexId / nextMyGraphVertexId / currMyGraphEdgeId / currMyGraphEdge MyGraph::VertexId currMyGraphVertexId = currVertex.refMyGraphVertexId; MyGraph::VertexId nextMyGraphVertexId; MyGraph::EdgeId currMyGraphEdgeId; bool currMyGraphEdgeExists; MyGraph::Edge currMyGraphEdge; //declare newVertexId / newEdgeId / newEdge m_VertexId newVertexId; m_EdgeId newEdgeId; bool newEdgeCreated; //generate neighbors to currVertex MyGraph::OutEdgeIt outMyGraph_i, outMyGraph_end; for(tie(outMyGraph_i, outMyGraph_end) = out_edges(currMyGraphVertexId, *m_myGraph); outMyGraph_i != outMyGraph_end ; ++outMyGraph_i) { //get nexMyGraphVertexId / currMyGraphEdgeId / currMyGraphEdge nextMyGraphVertexId = target(*outMyGraph_i, *m_myGraph); tie(currMyGraphEdgeId, currMyGraphEdgeExists) = edge(currMyGraphVertexId, nextMyGraphVertexId, *m_myGraph); if(currMyGraphEdgeExists) currMyGraphEdge = (*m_myGraph)[currMyGraphEdgeId]; else exit(1); //add/set newVertex newVertexId = add_vertex(m_searchGraph); m_Vertex & newVertex = m_searchGraph[newVertexId]; newVertex.currX = currX + 1; //to change newVertex.currZ = currZ + 1; //to change newVertex.refMyGraphVertexId = nextMyGraphVertexId; newVertex.prevVertexId = newVertexId; //add/set newEdge tie(newEdgeId, newEdgeCreated) = add_edge(_currVertexId, newVertexId, m_searchGraph); if(newEdgeCreated) { m_Edge & newEdge = m_searchGraph[newEdgeId]; newEdge.weight = sqrt(2); //to change } else exit(1); } } void AStarSearch::m_printSearchGraph(m_SearchGraph & _searchGraph) { m_Vertex currVertex; m_VertexIt v_i, v_end; printf("id\t"); printf("id prev\t"); printf("id ref\t"); printf("dist\t"); printf("cost\t\t"); printf("color\t"); printf("\n"); for(tie(v_i, v_end) = vertices(_searchGraph); v_i != v_end; ++v_i) { currVertex = _searchGraph[*v_i]; printf("%i\t", *v_i); printf("%i\t", currVertex.prevVertexId); printf("%i\t", currVertex.refMyGraphVertexId); printf("%f\t", currVertex.distance); printf("%f\t", currVertex.cost); printf("%i\t", currVertex.color); printf("\n"); } printf("\n"); } list<int> AStarSearch::m_getPath(m_SearchGraph & _searchGraph, m_VertexId _vertexId) { list<int> path; for(m_VertexId currVertexId = _vertexId; ; //cf if()... break; below for stopping condition currVertexId = _searchGraph[currVertexId].prevVertexId) { path.push_front(currVertexId); if(_searchGraph[currVertexId].prevVertexId == int(currVertexId)) break; } return path; } vector< list<int> > AStarSearch::m_getAllPaths(m_SearchGraph & _searchGraph) { m_VertexIt v_i, v_begin, v_end; for(tie(v_i, v_end) = vertices(_searchGraph); v_i != v_end; ++v_i) { _searchGraph[*v_i].color = white_color; } vector< list<int> > allPaths; tie(v_begin, v_i) = vertices(_searchGraph); for(--v_i;; --v_i) { //printf("curr vertex %i\tcolor:%i\n", *v_i, _searchGraph[*v_i].color); if(_searchGraph[*v_i].color == white_color) { list<int> newPath = m_getPath(_searchGraph, *v_i); list<int>::iterator currVertex; for(currVertex = newPath.begin(); currVertex != newPath.end(); ++currVertex) { _searchGraph[*currVertex].color = black_color; } allPaths.push_back(newPath); } if(v_i == v_begin) break; } return allPaths; } void AStarSearch::m_printPath(list<int> _path) { list<int>::iterator pathIt; for(pathIt = _path.begin(); pathIt != _path.end(); ++pathIt) { printf("%i\t", *pathIt); } printf("\n"); } void AStarSearch::m_printShortestPath(m_SearchGraph & _searchGraph) { printf("shortest path:\n"); m_printPath(m_getPath(_searchGraph, get_property(_searchGraph, graph_name))); } void AStarSearch::m_printAllPaths(m_SearchGraph & _searchGraph) { vector< list<int> > allPaths = m_getAllPaths(_searchGraph); printf("all paths:\n"); vector< list<int> >::iterator currPath; for(currPath = allPaths.begin(); currPath != allPaths.end(); ++currPath) { m_printPath(*currPath); } } ==================================================================================== Cheers, Damien

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Re: [Boost-users] multinomial tree-like container
by Hicham Mouline 01 Mar '10

01 Mar '10

-----Original Message----- From: "Hicham Mouline" [hicham(a)mouline.org] Date: 01/03/2010 10:53 AM To: boost-users(a)lists.boost.org Subject: Re: multinomial tree-like container Hello, Is there a library that provides a public container that has the structure of a tree where there are top nodes, and each node can have 0 to N children? regards, ----------------------------------------------------------------------------- I just found in the boost vault the tree-soc2006 container that seems exactly what I need. Has there been any changes since 2006 in that library? regards,

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boost::asio::deadline_timer precision issues
by Warren Seine 01 Mar '10

01 Mar '10

Hi, I'm writing a timer class which calls a function every n ms. I'm using Boost.Asio to achieve that. Please tell me if there is a better solution. The usual pattern with boost::asio::deadline_timer is to call `expires_from_now()' and `async_wait()' every time the timer expires. The solution works, however the timer seems to have (important) precision issues, as described in the sample code below. A simple counter is incremented every 20 ms, and is displayed (and reset) every 1000 ms. The value displayed should therefore be close to 50. In practice, it's closer to 40, which in unexplainable with such a simple piece of code. $ cat test.cc #include <boost/asio/io_service.hpp> #include <boost/asio/deadline_timer.hpp> #include <boost/function.hpp> #include <boost/bind.hpp> #include <boost/date_time/posix_time/posix_time.hpp> #include <iostream> static boost::asio::io_service* s_service = 0; static unsigned int s_counter = 0; struct timer { timer(unsigned int delay, boost::function< void () > callback) : m_timer(*s_service), m_callback(callback), m_delay(delay) { } void start() { m_timer.expires_from_now(boost::posix_time::millisec(m_delay)); m_timer.async_wait(boost::bind(&timer::handle_wait, this, _1)); } void handle_wait(const boost::system::error_code& e) { start(); m_callback(); } boost::asio::deadline_timer m_timer; boost::function< void () > m_callback; unsigned int m_delay; }; void increment() { s_counter++; } void display() { std::cout << s_counter << std::endl; s_counter = 0; } int main() { boost::asio::io_service service; s_service = &service; // Display the counter every 1000ms. timer t1(1000, display); // Increment the counter every 20ms. timer t2(20, increment); t1.start(); t2.start(); service.run(); } $ g++ test.cc -o test -lboost_system $ ./test 41 42 43 40 42 43 42 ^C My environment is GNU/Linux within a VM. My compiler is GCC 4.4 and I'm linking with Boost 1.42. Please ask me any detail that might be relevant. If that's an expected behavior, is there any way I can "trust" the timer? I couldn't find any documentation discussing the issue. Thanks, -- Warren Seine

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multi index container descending order, without reverse iterator
by Andrew Kokkalis 01 Mar '10

01 Mar '10

Hello, I'm using a multi_index container, non uniquely ordered by a float. I want to access it by descending order, but when i'm using reverse iterator, i cannot use erase. Is there an way to delete the last element? it--; is not defined. erase(data_set.end()) does not work , end indicates after the last element. Thank you very much, i'm in great hurry, and i don't have time to look the tutorials right now. Thank you in advance, Andrew Kokkalis

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[fusion] clarification on stateful unary function objects
by Matthias Vallentin 01 Mar '10

01 Mar '10

Hi there, While trying to use a stateful unary function objects, I stumbled over and old discussion from 2007 [1]. From the current Fusion documentation, I understand that the functor passed to the for_each algorithm must satisfy the Regular Callable Object concept. I presume that regularity, which I understand as replacing inputs with equal objects results in equal outputs, here implies that operator()(T& x) must be const. In other words, mutable function objects are not supported. As pointed out in [1], it is of course possible to bypass this restriction by defining the state that needs to changed as mutable. I was wondering if this is still the correct way to deal with mutable function objects, as illustrated in the small example below: #include <iostream> #include <string> #include <boost/bind.hpp> #include <boost/fusion/include/algorithm.hpp> #include <boost/fusion/include/container.hpp> struct container { struct printer { template <typename T> void operator()(T& x) const { std::cout << ++i << ": " << x << std::endl; } mutable unsigned i; }; template <typename T> void write(const T& row) { boost::fusion::for_each(row, printer()); } }; int main() { int i = 42; unsigned j = 7; std::string s = "foo"; container c; c.write(boost::fusion::vector_tie(i, j, s)); return 0; } Matthias [1] http://lists.boost.org/boost-users/2007/03/26338.php -- Matthias Vallentin vallentin(a)icsi.berkeley.edu http://www.icir.org/matthias

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Re: [Boost-users] [GIL new_io] range of gil floating point images
by Robert Lupton the Good 01 Mar '10

01 Mar '10

> Float and double are perfectly valid GIL channels, but their scope is ?inf to inf, so you cannot linearly interpolate from a float to an uint8, for example. Thus they are not as useful as bits32f This has been a nuisance for us too --- we use gil to represent data from a telescope, where the scaling is a real pain as the floating point numbers represent the data read from the detectors. It'd be nice if gil came with the needed typedefs for pure floating (32 and 64 bit) images/views (as well as the ones that scale in [0,1] which are presumably what others want). It's too late to call the unscaled types 32f, but isn't 32F still available? R

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[ptr_container] view_clone_allocator with associative containers
by Matthias Vallentin 01 Mar '10

01 Mar '10

I cannot get the view_clone_allocator to work with associative containers, as in the example below: boost::ptr_vector<int> vec; boost::ptr__map<std::string, int, boost::view_clone_allocator> map; int* i = new int(42); vec.push_back(i); std::string k("foo"); map.insert(k, i); >From the error message, it seems that the CloneAllocator is still of type boost::heap_clone_allocator. Why is this failing? It seems intuitive to specify the allocator as third parameter, similar to the example with ptr_vector where the allocator is the second argument. Matthias -- Matthias Vallentin vallentin(a)icsi.berkeley.edu http://www.icir.org/matthias

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array definition
by Damien MATTEI 01 Mar '10

01 Mar '10

hello, i have this definition that works: array_2D_double psf_cartesian_centered(boost::extents[range_ext(indiceBegin,indiceEnd+1)][range_ext(indiceBegin,indiceEnd+1)]); but i want to use this writing to improve reading of my code in a more natural way: array_2D_double psf_cartesian_centered2[ boost::indices[indiceBegin <= array_2D_double::index_range() < indiceEnd][indiceBegin <= array_2D_double::index_range() < indiceEnd] ]; unfornunately this does not work , i read one hundred times the boost tutorial and documention qhere it is written something like this should ... what is my error? regards, damien

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Have Boost random Library contained the function for generating Gaussian noise ? Can any one with kindness help me?
by fmingu 01 Mar '10

01 Mar '10

I am a new comer and using Boost library for math works. I want to know whether Boost Random Library contained the function for generating Gaussian noise. Or Gaussian noise can be easily generated by the functions in Boost Random Library? Or any other library compatible with the Boost Random Library? Can any one with kindness help me?

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best boost cc-mode style
by Russell L. Carter 01 Mar '10

01 Mar '10

Hi folks, I'm starting to get heavy into templates and it seems my ancient cc-mode customizations are a disaster when trying to format complicated template code. I'm now using emacs23 with cc-mode version 5.31.7. What's the best out-of-the-box cc-mode style for boost style template formatting? (Some googling revealed that Dave A. a long time ago made some mods to cc-mode, what style did they end up in?) tnks, Russell

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[Exceptions] Custom type in error_info value?
by Andrew Chinkoff 01 Mar '10

01 Mar '10

This is the test program I would like to be explained to me: #include <iostream> #include <string> #include <boost/exception.hpp> struct MyException: virtual boost::exception{ }; class MyClass { char* s; public: MyClass(const char* msg) : s(strdup(msg)){ } MyClass(const MyClass& c){ s = strdup(c.s); } ~MyClass(){ free(s); } }; void main() { MyException ex; ex << boost::error_info<struct my_tag1, MyClass>("qweqwe"); ex << boost::error_info<struct my_tag2, std::string>("asdasd"); std::cout << boost::diagnostic_information(ex); } This is the program output: > Throw in function (unknown) > Dynamic exception type: struct MyException > [PAUmy_tag1@?1?main@] = [ type: ?AV?$error_info@Umy_tag1@?1?main@VMyClass @@@boo > t@@, size: 8, dump: 50 69 10 01 b8 18 7f 00 ] > [PAUmy_tag2@?1?main@] = asdasd So, my question: what should I do with 'MyClass' to see the output like this: > Throw in function (unknown) > Dynamic exception type: struct MyException > [PAUmy_tag2@?1?main@] = qweqwe (Wow !!! Terrible dump is replaced with readable string here !!!???) > [PAUmy_tag2@?1?main@] = asdasd Thanks, Andrew.

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